i am looking at a shovelnose, and was wondering about the gears, i know i need to change them to a different size, the engine that was in it had 1200 hp, now the guy has 700 hp in it, what gears would i need to run a 500 hp? will 4-500 hp engine work in a shovelnose? . btw it is a 1975 sanger shovelnose two seater, with outboard steering. thank MAGOO...