A direct bolt on 4 barrel intake for the 3.8 is the one off of the 4.1 buick, that is if you can find it. The edlebrock intake makes no more power than than the stock one UNLESS you use the edlebrock "power package" with it. Whatever intake you use, you must limit the how much the secondaries open or WILL overfuel the engine and do nothing but make black smoke, have less power at full throttle, and be washing the cylinder walls down with raw fuel
🙁 . What most people don't understand about the naturally aspirated, carbed 3.8 is that it had reached it's maximum efficiency to that point with the current technology of the day. Hence the reason the next generation went multi-port injection, dis, balance shafts, redesigned heads. While almost everyone at the time was going to fuel injection of some sort, no-one, at least domestically, was doing distributor-less ignition, balance shafts, tall port heads, sequential injection, low resistance oil pumps, etc. Of course my opinion is biased as I grew up with Buicks as that was the ONLY car my grandfather would own OR drive
😀 . The Buick V6 was designed, from the beginning, from the time it was released in the early 60's, sold to AMC, bought back from AMC, to be a reliable, efficient people mover. With a few exceptions, that is all it was designed to do. And, IMO, it did it supremely all the way until it was replaced
😢 with the junk-*ss 3.5/3.6/3.9. I am not trying to discourage you from playing with your engine but just trying to give you some insight. Sorry about the long write up but I tend to ramble on when my meds kick in.
Btw. you can use a block-off plate from a
Grand National, which, when you look at it looks just like one from a chevy small block turned up side down.