Im wanting to swap my guts from an imco 2in shortie to a 3in shorty, is it the same guts as a mercury lower and same process to reinstall as a mercury lower. Reason for asking is a friend is going to help and he has done many mercury lowers, and said if they are the same it shouldnt be a problem

The -3" shorty will need a different (shorter) vertical shaft. Other wise it is the same. The Imco lowers use shims instead of a load ring, but either can be used. So long as you dont go WOT in reverse, it should not matter.

Dick

Or jump a wake and come back in with your props not spinning.

good point waconda.. I have never had a problem with the crush ring, but maybe if someone drives it that way, it could be a problem.. Anytime I tried that, it was trip and stuff time. Makes you think twice about doing it again.
I did have one friend that came back, but I have also found the race in a new Merc bearing carrier, not seated properly. I attributed it to that rather than a squashed crush ring. Good food for thought. Thanks!