I agree with Will. The 4.9 was the last true Pontiac V-8 engine. In its NA state it wasn't that big of a performer--but it is a classic. The older Bonnevilles are full frame, RWD cars--not unibody FWD like ours. This gives it a much nicer ride, and is easier to Mod than the later Bonnevilles that received McPhearson Struts and FWD. They are also a lot roomier.
My suggestion is to get it on the road first, mod as $ comes in. If you are looking for 4.9 mods, pick the boneyards for 4.9 turbo Trans Ams. Don't forget the tranny. It has been sitting a while, it should be flushed and have a new filter before it hits the road.
Yes it is a small V-8, yes it is a big car. But if you treat it right and fix it up, the mods will come later and you will have a true sleeper.
Welcome to the forum.
Retired Moderator, The Bonneville Club www.bonnevilleclub.com
RIP Oldsmobile, April 29
1995 Bonneville SE Supercharged (Stock)
Current Mods: Dirty GYM Sock air freshener.