will a 3.8 v6 fit in a 93 grand am 3.3 v6? what changes will need to be made?

many many changes will need to be made, u will need the trans for the 3.8 also, new computer, etc etc, a big job but can be done with money, patience and a lot of car knowledge, check out gmpowertalk.com for info, there have been many forum posts with this topic

You need to build up a 3800 Series II with a 4t65e matching transmition.
Motor mounts SHOULD be the same, but i wouldn't doubt it if they were not the same.... but the 3800's are BAD ASS.