Superchargers?

any kind of forced induction is going to be a pretty major mod if you're getting parts from a junkyard. My guess is you're worried about money, which is fine. But to be honest you're not going to be able to scrape much together just scrounging around for parts in a junk yard, especially since anything that does have a supercharger that would work on your car would probably not be in said yard.

As far as what sort of car you can steal off of, I really have no idea, but I really don't think you should want to. If you want to get more hp and have a reliable sturdy motor, your best bet is to buy it professionally made.

a supercharger is a major mod and is mod ive always work towards but the problem with putting a supercharger on your stock v6 is it wasnt buit for that much forced pressure from the added fuel so eventually you will blow a hole in the cylinder. about the only thing you can do is research up on cars that had factory supercharged mmotors and try and replace the whole motor. for example the ford thunderbird super coupe came stock with a supercharged v6 motor but they are far and few to find and expensive there was also another factory supercharged v6 and i think pontiac made them on the 3800 but i cant remember which car it was put on, that supercharger might also work becuse the 3800 and 3.8 and relatively close to the same motor. But this isnt something you can do cheap because it will cost you a lot more later on down the road so researching some more and trying to piece together your project is a better idea