The parts from 35 to 50 are a total different design. In other words they are two different powerheads.
You may be able to achieve 50 hp with nitrous oxide injection, but I don't think they make a kit, and if they did, the motor would probably self destruct quickly.
It wouldn't be worth the effort to do this, the blocks, heads, and everything are completely different. You are much better off just finding a 50hp to play with
