Mark, could you tell us what year(s) you are looking at? Also carburetor/fuel injection, turbo/supercharged, manual/automatic etc. Buick didn't make an F-body car, but engine applications between the brands should be similar.
Buick did not build any rear-wheel drive cars with the V6 after '87. At one time or another, every GM brand used a version of the Buick V6. Would have to look it up, but I think some Camaros even used the 231 V6.
One idea would be to pick up a factory Firebird shop manual for the desired year and study the engine chapters in detail. There should should be some used copies available on eBay at reasonable prices.
Some Buicks were equipped with the 403 V8, but it is an Oldsmobile engine.