Yes, it has been done all the time. You need a longer drive shaft, water tube and shift rod coupler, plus the 5" extension. No, 6 horses are all you're going to get from it, sorry.
ok, so converting to short shaft in need shorter drive shaft,shorter water tube pickup, shorter shift rod coupler......sounds like it wouldn't be cost effective unless I have access to an old junk motor....and 6hp is 6hp.........thanks 1946Zephyr for the fast response!!!!
Yea, if you want to save a few bucks, go to the top secret file at the top thread and try any of those salvage yards for your parts. It'll be a lot cheaper than buying new. Yea, the 10 hp (9.9) is a totally different motor than the 6 and has the same cubes as the 15. The 6 of your year has the tiny powerhead like the 5.5's did of the '50's Great motors though and an excellent design. They are much improved over the 5.5.