i am swapping a v6 3.8L buick engine with a 200 matic tranny to a 350 5.7L with a 350TH tranny... How difficult and what mods do i have to do to drop it in?????/

i'm not sure this is the best place for things like that, it sounds like a really big job but there may be other sites that have some detailed walk throughs of that kind of thing

Sorry bud, V6 to V8 swaps almost ALWAYS cost more. I had a 94 Camaro V6 that I looked at swapping the the LT1 total cost was about 8 grand, me doing all the work. My advice, sell the 6 and buy and 8, save some money and the headaches