I was in your position a while back, so I'll try to aim you in the right direction since I'm still an amateur in this. This site along with these have been the most helpful if you have the time to search and read. There is a thread on buying these cars
Gnttype.org. - google it with what your searching, its kind of a pain to search on it. Or just read all of it.
Vortexbuicks - super informative with alot more organization.
As for the car, just pay attention to the seller, as some are full of crap cause they are selling crap. I usually came across rusty floor pans, and rust spots in the trunk below the windows. You'll probably end up with a modded car that you'll need to sort out, which I found kinda fun. Engine work is not cheap, so listen to the veterans when they chime in on this topic.
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