TOPIC: New member...1979 Thompson Sidewinder

have you contacted Sidewinder. sidewinderboats.com/ and Sidewinder has a facebook page. www.facebook.com/sidewinderjet

Ike wrote: have you contacted Sidewinder. sidewinderboats.com/ and Sidewinder has a facebook page. www.facebook.com/sidewinderjet

Thanks...I didn't realize Sidewinder was still making them, I'll send them an email and see if they have any old literature. I did find that Sidewinder group on Facebook, I'm not on FB very often so haven't had a chance to post there.

Did a little more searching. Found a history of Sidewinder at www.retrorunabout.com/sidewinder.html Caution, all the way at the bottom in the notes it says,
"Advertisements - www.vintagejetboats.com/content.php?248-Sidewinder
remade by Global Marine Specialties - sketchy guy in Kent www.sidewinder-boats.com/portal/windertalk/showthread.php?t=4260 "

That's the link I posted above. I don't know if he has any connection to the original Sidewinder Boats. They sure look like Sidewinder.
There used to be a Sidewinder owners forum but I can't find it. Must have been taken down. I know that Sidewinder owners here in the PACNW have annual meets over in eastern Washington, but since the forum has disappeared I can't find any info.

There is a very long thread about Sidewinder on BoatDesign.net, a forum primarily for designers and builders, but just about anything to do with boats shows up there. www.boatdesign.net/threads/sidewinder-information.3523/ I haven't read through the whole thing but you might be able to glean some information from it.

Thanks again Ike. I've seen the Sidewinder history a couple nights ago from a different site. The thread at the boatdesign page, I've read that also a day or so before we brought ours home. Was trying to find info on it before we jumped in. There was a lot of looking for parts, looking for info, and selling boats in that thread.
Some good info too if I remember correctly. There was also a lot of talk of Sidewinders on some powerboat forum but it's pretty much go fast stuff and talking about correcting chine walk. Usually all the threads that had any detailed pictures were screwed up thanks to Photobucket.
I seen a lot of posts mentioning that now gone Sidewinder forum. Sounds like that would have been the place to find anything I needed.
I'll keep crawling the web looking for bits lol.

A couple of sites you might want to look at:
Performance Boats www.performanceboats.com/search.php?searchid=45185549
Scream and fly www.screamandfly.com/forum.php
Scream and fly seems to come up a lot in searches on sidewinder, but I know nothing about the site or their forum.
Performance Boat is a carry over from the old Hot Boat Magazine forum which is now defunct. A dam..d shame because I loved Hot Boat Mag. Unfortunately the owner passed and the family sold the mag to someone who tried to turn it into a "family friendly" boating mag. It went under. Most of the members of the forum transferred over to Performance Boat magazines forum. I have seen a lot of references to Sidewinder boats on their forum over the years.

Yeah, screamandfly, that's where I found a bunch of go fast topics. I just did a quick look at performanceboats and seen some interesting stuff. I've thought if the Merc 470 isn't any good it would be sweet to drop an aluminum block 5.3LS in it and sure enough there was a thread about it lol. Figured the aluminum block LS should be plenty light enough as they put 455 Olds in the 18'ers. But, I don't think I'll go down that road. All the extras such as exhaust and water pump will drive the costs up pretty fast. If the 470 turns out to be a dud I'll buy a junk boat with a newer 4.3 and swap everything in.
I'll look some more at the performanceboat site and see what I can find. Been finding some good reading but there are so many broken picture links.

here are 2 pictures of friends sidewinder from the late 1970s. Notice the tall motor hatch. It was a 4 cylinder with MerCruiser outdrive, BUT it had a Turbo added. It would run over 60. I drove it once and saw the speed for myself. Rode in it many times and skied behind it. Maybe you could find someone with the right sized turbo for a crazy good price. I know nothing about them. I just wanted to share another thought to keep weight down. The extra power allowed for more speed without too much trim so you could avoid chine walking like some of the high powered outboard sidewinders that would trim out to crazy chine walking. My memory is fading... maybe this was one of the splashed copies of the sidewinder.

Thanks, kinda interesting. Do you know if he made that engine hatch? The side looks like it has the same molded shapes that the hull has, but yet the engine hatches I have seen were more shapely.
Mine is completely missing so I have to build something up.Thought about using foam boards to glue together and shape and nice form to glass over but I've been told they use polyurethane foam board for glassing over, it's expensive from what I've found. Great for saving weight but harder on my wallet than I want lol.

I had two boats quite awhile ago that had the 470. The internal alternator was a big problem for some but it looks like that problem is solved for you. Both had internal cooling. Cooling on the back cylinder was somewhat a problem but not a huge issue. That motor has killer torque and can swing a large prop with any issues. Check the outdrive bellows for cracks and leaks. The ones I had vibrated slightly so a check of the motor mounts to the wood/glass hull is worth a peek. Here's a link that you might find interesting.
www.sterndrives.com/470information/470coolantleakrepair.html

That turbo charged boat was bought used, so don’t know about engine hatch. I thought I remember them saying previous owner custom made it. With the notches and perfect color match, they did a great job. Maybe a boat repair shop or even perhaps a body shop that did fiberglass corvette work. That boat was a cool sleeper. Hard to tell from the old picture, but it was purple metal flake with a silver metal flake stripe.

63 Sabre wrote: I had two boats quite awhile ago that had the 470. The internal alternator was a big problem for some but it looks like that problem is solved for you. Both had internal cooling. Cooling on the back cylinder was somewhat a problem but not a huge issue. That motor has killer torque and can swing a large prop with any issues. Check the outdrive bellows for cracks and leaks. The ones I had vibrated slightly so a check of the motor mounts to the wood/glass hull is worth a peek. Here's a link that you might find interesting.
www.sterndrives.com/470information/470coolantleakrepair.html

I read up on these engines before I got the boat as I've had no experience with them. I did see that those using them said they are quite tourqy, that's a good thing. When I read about the charging system set up it was a WTF moment lol. Seemed too much like a snowmobile with a bad idea for the water cooled regulator.
If the engine is ok, I had plans on replacing the bellows before it hit water anyway, just good insurance. And also resealing the water pump after reading about possible issues there. A quick check over the other day sweeping the leaves out, the engine mount and attaching areas look really good. Thinking the floor has been up and everything replaced at some point. Might not get too much farther for the season, got snow already today so it'll probably get buttoned up for the winter sleep. I don't have a garage so everything gets done in my driveway.
That link you posted, worth every word in it! Good read, I'll bookmark it for rereading again. Thanks

Dr.Go! wrote: That turbo charged boat was bought used, so don’t know about engine hatch. I thought I remember them saying previous owner custom made it. With the notches and perfect color match, they did a great job. Maybe a boat repair shop or even perhaps a body shop that did fiberglass corvette work. That boat was a cool sleeper. Hard to tell from the old picture, but it was purple metal flake with a silver metal flake stripe.

Makes sense being the shape of that hatch. Was a nice touch with the notches. Purple could be cool, like the Plumb Crazy Purple that Mopar used back in the day of cool cars! My Sidewinder has been repainted at some point, and not a very good job. A lot of it is peeling so I don't think proper prep was done on the primer before they sprayed the color coat. No biggie. I have a Binks Model 5 spray gun that I've used quite a bit so I'll repaint it. I kinda like the metal flake too.

What area north of the Mason Dixon line are you in. Sounds like you have the same weather issues Dr. Go and I have. Normal temps are average mid to upper forties. Lows are now in single digits and the ground is freezing.

Hi,
My family was a Sidewinder dealership from 1970 to 1974. After Thompson bought Sidewinder (Sidewinder amassed huge legal bills for legal suits again it's patented design - the Sidewinder Super 16 Outboard was the most copied patented boat design ever), it is my remembrance that Thompson switched to upholstery over wood motor boxes (as they did for their other boats), so that is likely why yours is missing along with the rest of the interior. The purple and silver boat, in my opinion, shows a factory stock fiberglass motor box. I have added three pictures from our 1973 Sidewinder brochure of the 16' Stern Stern Drive. There was an aftermarket turbo charger kit back in the day for the Mercruiser 140. The Mercruiser 470 was not introduced until the 1976 year model (we were a Mercruiser dealer from 1962 to 2003). I am not aware of a turbo kit for it however.

Regards,
Joe
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Well that cover looks like it. And I do believe they had the 140. Sorry I wasn’t paying attention to that detail. The Dad did remove the name put on the boat... Purple Haze... I kind of liked it, but I was 16 and he was 55... still made him an instant cool Dad in our eyes... was a big step from an Evinrude sweet 16 in grey with about 90hp. Thanks for those dealer brochures.

63 Sabre wrote: What area north of the Mason Dixon line are you in. Sounds like you have the same weather issues Dr. Go and I have. Normal temps are average mid to upper forties. Lows are now in single digits and the ground is freezing.

I'm in the Socialist Republic of New York lol. About 40 miles south of Syracuse. it's 25 now, got a couple inches of snow today.

Ferguson_Poole wrote: Hi,
My family was a Sidewinder dealership from 1970 to 1974. After Thompson bought Sidewinder (Sidewinder amassed huge legal bills for legal suits again it's patented design - the Sidewinder Super 16 Outboard was the most copied patented boat design ever), it is my remembrance that Thompson switched to upholstery over wood motor boxes (as they did for their other boats), so that is likely why yours is missing along with the rest of the interior. The purple and silver boat, in my opinion, shows a factory stock fiberglass motor box. I have added three pictures from our 1973 Sidewinder brochure of the 16' Stern Stern Drive. There was an aftermarket turbo charger kit back in the day for the Mercruiser 140. The Mercruiser 470 was not introduced until the 1976 year model (we were a Mercruiser dealer from 1962 to 2003). I am not aware of a turbo kit for it however.

Regards,
Joe
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www.fergusonpoolemarine.com

Thanks, Joe. Those picture do look like the ones Dr Go put up. Guess I'm going to have to find Thompson specific literature or pictures. I did find a couple Thompson Sidewinder pictures, one was a jet so not relevant here, the other was an I/O w/120 but it was a 1984 and the deck was different than mine. I may have to get creative and built something to suit lol. I really don't like the lines of the '73 engine hatch anyway lol.
That's interesting that a turbo kit was offered back then, turbos really haven't gotten any popularity until fairly recently. to offer them back then seems like some pretty gutsy thinking. I like it.

A Google search shows this forum thread and picture of (I think) the turbo kit I remember: forums.iboats.com/forum/engine-repair-and-maintenance/mercruiser-i-o-inboard-engines-outdrives/607583-mercruiser-140hp-running-rough

Regards,
Joe
www.fergusonpoolemarine.com
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Friend mine had one with a 460/Berkeley jet. Raced him one time with 4 people both boats. My Switzer/XS Merc had him top end easy. I lay off the foot, and he shoots in front and with JetOVater up. I saw it coming like a fire hose and a front seat "DUCK"! The two back didn't duck as never saw it coming! Too much fun in the crazy 70's.
But I got back at him when HE wasn't looking!

Ferguson_Poole wrote: A Google search shows this forum thread and picture of (I think) the turbo kit I remember: forums.iboats.com/forum/engine-repair-and-maintenance/mercruiser-i-o-inboard-engines-outdrives/607583-mercruiser-140hp-running-rough

Regards,
Joe
www.fergusonpoolemarine.com
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That's a pretty slick setup. Never really cared for turbo'd gas engines with carbs for obvious reasons but they do generally work well. If they weren't so damned heavy I'd put a 6.5 GM (Detroit) turbo diesel in my Chieftain.
I did have one of the little Dodge Shelby Turbos and that thing would fly for what it was. Fuel injected so ne need weird carb setups.

Would probably be pretty easy to adapt a supercharger from one of the newer cars to a 140 Mercruiser though. No heat issues and special exhaust to worry about either.

Robby321 wrote: Friend mine had one with a 460/Berkeley jet. Raced him one time with 4 people both boats. My Switzer/XS Merc had him top end easy. I lay off the foot, and he shoots in front and with JetOVater up. I saw it coming like a fire hose and a front seat "DUCK"! The two back didn't duck as never saw it coming! Too much fun in the crazy 70's.
But I got back at him when HE wasn't looking!

I have no experience with jet boats, or even seen any on the lakes, so never understood running with a huge rooster tail. Other than the cool factor. Would seem to cut top speed to me. Would be nice to have though. The dock at my uncle's camp gets a bit close to shallow at times. Wouldn't be an issue with s jet boat. Some areas of the lake are kinda close for a prop boat too so gotta be real careful fishing.
They had quite the HP difference between OB, I/O, and jet. Was it 400+ HP for jet I think, these I/O were 170 max. Otherwise I wouldn't be opposed to dropping a V8 in mine lol. They're all over in parts boats.

FrankenCub wrote:

Robby321 wrote: Friend mine had one with a 460/Berkeley jet. Raced him one time with 4 people both boats. My Switzer/XS Merc had him top end easy. I lay off the foot, and he shoots in front and with JetOVater up. I saw it coming like a fire hose and a front seat "DUCK"! The two back didn't duck as never saw it coming! Too much fun in the crazy 70's.
But I got back at him when HE wasn't looking!

I have no experience with jet boats, or even seen any on the lakes, so never understood running with a huge rooster tail. Other than the cool factor. Would seem to cut top speed to me. Would be nice to have though. The dock at my uncle's camp gets a bit close to shallow at times. Wouldn't be an issue with s jet boat. Some areas of the lake are kinda close for a prop boat too so gotta be real careful fishing.
They had quite the HP difference between OB, I/O, and jet. Was it 400+ HP for jet I think, these I/O were 170 max. Otherwise I wouldn't be opposed to dropping a V8 in mine lol. They're all over in parts boats.

Yep, squirt boats jet up? Really makes zero diff down or up as its thrust of water, just like a jet engine shoving air. But My Switzer with the XS Merc ran a surfacing prop, and my Rooster Tail is the real deal, even if went thru 2 gear cases bullet (SS 2B 14x28 prop) expanding the case, shot the guts out once. Cheap to fix then...(and young and stupid, and who cares! I got no complaints jets! Boats a boat, long as it floats!!

Robby321 wrote:

FrankenCub wrote:

Robby321 wrote: Friend mine had one with a 460/Berkeley jet. Raced him one time with 4 people both boats. My Switzer/XS Merc had him top end easy. I lay off the foot, and he shoots in front and with JetOVater up. I saw it coming like a fire hose and a front seat "DUCK"! The two back didn't duck as never saw it coming! Too much fun in the crazy 70's.
But I got back at him when HE wasn't looking!

I have no experience with jet boats, or even seen any on the lakes, so never understood running with a huge rooster tail. Other than the cool factor. Would seem to cut top speed to me. Would be nice to have though. The dock at my uncle's camp gets a bit close to shallow at times. Wouldn't be an issue with s jet boat. Some areas of the lake are kinda close for a prop boat too so gotta be real careful fishing.
They had quite the HP difference between OB, I/O, and jet. Was it 400+ HP for jet I think, these I/O were 170 max. Otherwise I wouldn't be opposed to dropping a V8 in mine lol. They're all over in parts boats.

Yep, squirt boats jet up? Really makes zero diff down or up as its thrust of water, just like a jet engine shoving air. But My Switzer with the XS Merc ran a surfacing prop, and my Rooster Tail is the real deal, even if went thru 2 gear cases bullet (SS 2B 14x28 prop) expanding the case, shot the guts out once. Cheap to fix then...(and young and stupid, and who cares! I got no complaints jets! Boats a boat, long as it floats!!

There's a Switzer local to me for sale. To rich for my blood but I'm sure worth everything he's asking for it. It's nice, really nice. Don't remember what's on if for an engine. This Sidewinder came up local too, wasn't looking as I have a 21' Starcraft Chieftain I'm restoring but who am I to turn down a Sidewinder for the price of a cheap trailer. The intact windscreen is worth more than I paid for everything lol
Around here registrations for boats and trailers are rare, I don't know why but no one has them. This has both, another huge plus. Damn near impossible in NY to get paperwork for a trailer if it's missing.

So I got to looking at the Coast Guard plate and there isn't a HP rating on it, just has max weight of engine and fuel not to exceed 850 pounds.
Are they including the outdrive in that weight?
This could make things interesting it the 470 turns out to be no good. There's a bunch of parts boats around here with SBC engines lol.

Ignore it, means nothing. And a BB Ford weighs like 720, jet outdrive very little. A old 280 prop Outdrive total, only 150. Bet a jet OD be like 50 lbs.

The capacity label horsepower rating does not apply to inboards. Yes the weight includes the drive, but as was said, jet drives don't weigh as much as a sterndrive.

Ok, my rough guesstimates from the web show a SBC at 575, Alpha leg at 85, and transom assembly at 50. Total of 710 leaving 140 for fuel. Should be good.
And if these Sidewinders have a 20 gallon fuel tank that's 120 for gas. Down to 20# to spare.

It doesn't matter! HP rating more for a Outboard hanging off the transom. Inboards don't count as in the boat, between the stringers. Little stress transom. Pretty sure any BB, and a toss a couple fats kids back there, and zip will happen.

Robby321 wrote: It doesn't matter! HP rating more for a Outboard hanging off the transom. Inboards don't count as in the boat, between the stringers. Little stress transom. Pretty sure any BB, and a toss a couple fats kids back there, and zip will happen.

I kinda figured that after you and Ike posted earlier. I just wanted to be good with the weight issue. A lake near me I'll spend time on is plagued with police boats and guys I know that use the lake a lot stressed that everything needs to be proper there and to expect to be boarded for inspection. I'd hate be over the spec'd listed weight and police give me an issue over it.
Anyway, all the Sidewinders I've seen on the net that have V-8s were Super 18s, mine is a 16. The 16s I've seen were all OB or 4cyl I/O.

The water cops have no way of knowing if you have exceed the boat, motor and gear weight. They really only count how many bodies are on the boat and compare that to the number of persons on the label. We (we meaning when I worked in CG Boating Safety) were the ones who required the label and set the standard. The important number is the weight, but they aren't going to yank the engine out and weigh it. So I wouldn't worry about it.

I figured the New York State Police that patrol these lakes might know rough numbers. This state will go to any length to make a buck.
I'm probably only going to have 2 seats in it anyway. Just for my wife and I, so no worries of how many I have aboard.

Putting aside the capacity plate and inspection concerns voiced, I think you are going to have to do a lot of very careful donor selection at the very least. A 1979 Mercruiser I drive is not going to long "stand-up" to a high power small block, and especially so with any wave jumping that will eventually occur with the top speeds likely envisioned. A Bravo One drive is best, or an Alpha One/SS drive would be minimum, and these should be installed higher ("X" dimension) like "jacking" an outboard motor, necessitating transom hole and engine mount changes. Stern weight (hull balance) with a 16 foot will be an issue unless aluminum heads and block are also part of the mix, possibly necessitating a closed cooling system also against brackish or saltwater damage. Now once all of these are addressed, you still have "less" hull than desirable for the speed involved, and why so very few 16 foot I/O boats are seen for "performance" use. Sorry to come across as a wet blanket.

Regards,
Joe
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Joe, that was great to see your experienced professional advice. You offered the complete recipe that already eliminated all of the shortfalls of experimenting. I really also appreciate all of the good and professional advice on this site. Based on my past experience watching a few outboard models race me back in the day and driving that Turbo boat, I would think you really would want to be careful using trim as I remember that would exhibit the very definition of Chine Walk that would often cause the need for quick shut down and re-setting of the hull. I would think that would be even more of an issue with this higher HP...just feeling it out rather than grabbing full trim first time out. I did see one other persons solution for their need for speed (but would take lots of changes). He took an outboard Jetflite Glastron which I believe is less that 15' and only rated for like 85hp outboard and decided to cut away the outboard motorwell, added stringers, then installed a 350 Chevy small block (this is in the 60s) and use a V-drive. The angle of the shaft forced the hull to stay wet and press into the water to help him avoid chine walk...he could hit 85mph. He also could jump that boat 3' off the water to the prop from an idle. The identical boat with a 110 merc would chine walk in the high 40's to low 50's with full notch position (he had no trim). That boat with the v-drive was wicked quick. I believe it is still in existence...I need to find it lol. Just wanted to throw you a curve with a crazy thought. Sticking to the professional advice of Joe is much wiser and likely will be more satisfying (and keep your boat more like its stock look and a better Sleeper). That V-drive V-8 was exposed, so unless you were a quarter mile away from it, it was no sleeper to the trained eye and ear (with above water exhaust). Good luck and keep us posted. I will stop sending you knuckle head ideas...just thought you should know.

Toss in anything ya want. Only caution me here is this "alternator upgrade". If used it It BETTER be a CG approved "Marine" Alt, not auto (as carb, fuel pump, distributor, more) or ya gotta good boom maker in the soon to me made dog house.

Ferguson_Poole wrote: Putting aside the capacity plate and inspection concerns voiced, I think you are going to have to do a lot of very careful donor selection at the very least. A 1979 Mercruiser I drive is not going to long "stand-up" to a high power small block, and especially so with any wave jumping that will eventually occur with the top speeds likely envisioned. A Bravo One drive is best, or an Alpha One/SS drive would be minimum, and these should be installed higher ("X" dimension) like "jacking" an outboard motor, necessitating transom hole and engine mount changes. Stern weight (hull balance) with a 16 foot will be an issue unless aluminum heads and block are also part of the mix, possibly necessitating a closed cooling system also against brackish or saltwater damage. Now once all of these are addressed, you still have "less" hull than desirable for the speed involved, and why so very few 16 foot I/O boats are seen for "performance" use. Sorry to come across as a wet blanket.

Regards,
Joe
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Thanks Joe, no wet blanket felt. All good information. Which I've actually been reading into the past day or two.
A little more info on my end. I dont have plans or needs for speed really, I worked that out in my younger years lol. Even 50 is plenty fast enough. Im more into acceleration anyway. As far donors, I am most likely going to pick up a whole boat and remove everything from it, the whole drive system. That way everything is matched. Here in NY there are a ton of boats that go really cheap because the floor, stringers, and transom are now the consistency of mulch. No one wants to invest the time and money to rebuild them, even with good running drives. I'm also near the Finger Lakes so no salt or brackish water to worry about.
My first thought was a donor boat with a 4.3 Merc but there just doesnt seem to be as many as there are 5.0 and 5.7 boats. I'll be staying completely stock with the engine anyway. No performance mods. I have seen plenty of 3.0s and such, but why go lower HP?
I did also read into changing the X dimension when making drive or performance changes. So hopefully whatever the donor boat has, it's the same lenget as what's present now
There isn't much room, if any, to raise it much.

Robby321 wrote: Toss in anything ya want. Only caution me here is this "alternator upgrade". If used it It BETTER be a CG approved "Marine" Alt, not auto (as carb, fuel pump, distributor, more) or ya gotta good boom maker in the soon to me made dog house.

Yep, know all about the CG approved goodies. This is my 5th boat so not new to this. My first was a '64 Johnson Deluxe with the Buick V-6, I really liked tha boat. Should have kept it. I was the second owner and it spent its whole life in a garage when not on the water. Very well cared for. Second was an old tri hull that I didnt keep around long, couldn't stand it. Third was a 15' MFG v hull with a 40hp egg beater, 4th and being restored is a '74 Starcraft Chieftain with the l6 I/O. And this Sidewinder.
I've seen a couple boat fires so pretty good about making sure things are right so I dont end up in that situation.

Crazy side thought. I am not sure if your 3.0 or 4.3 will give you 50mph, but I do know that one of those Land-n-Sea Torque Shift Props in the lower pitch will give great hole shot and acceleration. I/Os usually use the 26 pitch that starts at 11 pitch and adjusts variably to a maximum of 26 pitch. There are set back screws that will limit the maximum pitch several pitches. I run the 32” pitch that varies from 14” pitch out to 32. For me, my limit screws are set at 26. I can launch my 20 foot 1000 pound open bow with a stock 200 outboard. I will try to post a picture and also try to link a video. I see them on eBay here and there from 250-350 or 400. They sold for over a grand. I was saving 300 bucks in gas over a low pitch ski prop when pulling a lot of skiers... maybe 21 days on the water. It won’t push more top end than your hp would produce with the perfect prop, but the acceleration will smoke a standard speed prop. that picture is from an idle and not jumping any waves.

Here is the old video. It is low quality but should show you how 2 identical inboard/outboard boats perform side by side. The company is out of business, but someone bought remaining items and believe they are making some replacement internal parts. I just checked eBay and found 3 props when I searched for Torque Shift Prop. Look for the 26 stamping. I can read it on 2 of them, but can see the number on one. 2 have solid hubs and one has the rubber shock hub. At these low pitches, they don’t bang into gear too hard because they start very low pitch. Mine is a solid hub and been running almost 20 years.

Thanks, I saved that search! That's pretty interesting. I've never seen them before. Looks like the first one shows 226, second one 726, and the third 826.
I'm not really sure what the claimed speed should be, just rough guesstimating from what I've read at on of the powerboat forums. They were getting an easy 65mph with 150 egg beaters and most were running Super 18's. I'm sure the lighter weight engine helped. Some of the guys were getting 70+ on gps. So I don't think 50 is out of the question being a light hull that will be mostly out of the water. If I went with one of the 4.3 Mercs it could be 190-250hp. Now if it were Volvo, their ratings start at 240 and go to 280hp with the V-6. All depends on what I find for a reasonable parts boat. I like those variable pitch props though. Have you tried trimming down some to keep more bow down more on launch? That would make for a great holeshot!
I gotta watch that video again lol.