Re: '57/'59 35hp powerhead swap?
No, the '59 uses a dual-line water pump to recirculate the water. The '57 does not. Consequently, the powerhead-to-midsection mating surfaces are different. I believe a '58 Super Seahorse (not Seahorse) would work. If Chinewalker, FR, Joe, or Paul comes by, they can shed more light.
