Will it fit? Yes. (How good a machinist are you?) Is it a direct bolt on? No, far from it. Will it add 5 hp just putting on a carb? No.
i'm not a machinist,but i have a friend that is. what are my options and what will i gain by doing it ? thanks
You will gain next to nothing the the 15 is 13 cu. in.
the 20 is 31 cu in.Its pretty obvious the the 15 is allready pretty much at its max.It's possible a 20 hp carb will make it slower and more difficult to operate.
With stock port timing you're only gonna get so much fuel / air in. And out. You could build an adaptor but the stock hood and pans aren't going to work any more.
