i'm converting an older cig from trs to ssm3a & raising the x 2inches. should i expect a speed loss due to turning bigger drives?

DJD, Dave Dall, might be able to give you some information on this change as he did it to the 38 Cigarette I purchased from him.

I have been looking into this conversion as well, from what I`ve been told you will see a 3-5 mph increase

I'm with Biggus.

BTW, 2" may be conservative. The III turns a bigger prop and is intended to be semi-surface piercing. The additional length of the drive also allows for additional drive height. I've gained speed even with a SSMII to SSMIII conversion (about 3 mph on a 31' cat), increasing the drive height about 1" in that application.
Gary

after exhaustive resarch, have done the refit trs to ssm3's. you need to move up 3"min w/o notch transom and 4" with. I also changed power so I cant tell what it gained.