TOPIC: Difference in 50 hp and 55 hp? Just the carb?

I've been trying to find a 50 or 55 hp Johnson from the 1970's age. In the late 70's they started making 55 hp's. All the 50 hp's are usually from the early 70's. I'd rather have a 55 hp to get the most hp I can out of a lightweight 2 cylinder but the 55 hp's seem to be a little harder to find than the 50 hp's. I've located a 1972 50 hp for sale and I'm wondering if the carb was the only difference in these two motors (50 and 55)? Can I put a 55 carb on it? Thanks in advance.

Well, not knowing about the particular engine you're talking about. I would venture to say that if the carb is bigger, then the fuel pump would also have to be bigger as well as to not cause a lean condition. Just a guess...maybe someone with experience in this could chime in

If "push comes to shove", you can look up both motors on;
shop.evinrude.com/
and compare part numbers of the two motors on any and all items. Just go to parts - Johnson - and the year of the motor you're looking at.