I've build a bunch of motors for cars, but none for marine use. I've got a 21' 1985 Scarab with a stock 350 in it now. It will run 59 on the GPS. I've got a 400 block and crank laying in the garage that I'd like to build for this boat. I know that with a marine motor you want to make the power down low and peak out around 5000rpms. Can someone give me some info on the type of cam, heads, and compression that I should run. I think CompCams makes a 264 X-treme marine cam that might work OK. What do you think? How much power should it make? Will it tear up my Aplha drive?