What Size 4bbl for 81 buick 3.8

[MrSony]

If i was to do a buick 350 swap what all would be involved and what all would I need?

Nothing. DIRECT swap. Only thing you could use is new motor mounts. You just buy the cheapy 15$ V6 g body mounts from the parts store. Everything swaps over. Brackets, power steering pump, alternator, wiring, hell the distributors might even fit but you'd need a V8 cap. If you only have two bolts on the front of your timing cover on the bottom where the oil pan bolts on you can swap timing covers too. If you want some grunt that is 100% drop in read to go, a Buick 350 is the way to go. The 3.8 is literally a 350 Buick -2 cylinders. That's how it came about in the late 70s with the oddfire V6. I will warn you, it will NOT be as cheap as a chevy swap but it's better than the V6. Plus the 350 Buick is 150lbs lighter than a SBC in all cast iron form. If you go this route you will not look back. I did it and I love it.