TOPIC: 1969 SIlverline Riviera SS with Original vinyl top

Hey folks From what I can tell I have a 1969 Silverline Riviera SS with the Original vinyl top and frame. The Stringers and floor are rotted out and im in the process of redoing it all. One thing I've noticed is there is no flotation foam in the boat at all, is this normal? Also the boat is rated for 85 hp max and I have a 90 hp do you really think 5 hp will be considered over powering for the boat?

And last thing does anyone have production numbers for the silverline Riviera SS boats? I cant find anything.

Just some thoughts: if your 85hp is original, it's HP was likely rated at the crankshaft. If your motor is more modern, perhaps it would be 90HP rated at the prop shaft (which could mean it has even more comparative horse power at it's crankshaft...and therefore could seem more like a 15++ more HP difference. There are motor experts here that can give you exact years of when that rating system changed and what they believe is the "real" HP difference. I will let others who know your boat hull speak about handling with more HP. (Props and load in boat can make big differences too). Important thing to check: (is the Transom rotten like the other parts?) Hope others jump in. Good luck with everything!
Dr.Go!