I was wondering if i could use another 3000gt tranny of the same generation for this? because it has 218hp instead of 222hp...sorry for the noob question.

 

You can use any DOHC based tranny - just know that going from MT to AT (or vice versa) is a major undertaking.

There is no difference really between your DOHC and another - all engines have that much variation from engine to engine no matter how similarly engineered they are.