41hatteras

Swapping out a sick TRS for a Speedmaster III on an old Magnum Raceboat. Can anyone give me a ballpark on how far below the keel I want to locate the propshaft? While the boat is barebones and light for a Magnum it is probalby heavy compared to most modern boats. I will be running around 500 hp initially. I have seen suggestions of everything from 2.5" all the way to 6" in old forums. I have tried to contact the factory to no avail. Any help would be greatly appreciated.

CIG3

I'd start high, you can always space it down. I'd say about 3" ould be a good start. You are probably gonna have to cut the rub rail area to get the gimble that high.

rdoactive

Better check. I dont think you can use spacers on an early SSM III.