3.8 fuely top end swap?

[85 Cutlass Brougham]

GM used Series II heads on the turbo 3.8 installed in the 1989 Trans Am 30th Anniversary cars so that they would fit in the engine bay. However, I would just try to do a complete swap out of a 4th gen before I would try to convert your old engine. Then again, I would not do either because the price and complexity would be prohibitive compared to the gains you would receive.

 

[88ss408]

i looked up info on the buick v6 for a friend once. and as far as i could understand even tho that they are all 231ci or 3.8L displacement thats about the only thing they have in common!
the old school 3.8 rwd and then they adapted it for fwd aps(later known as pre-series 1)and then there is the series 1 series 2 series 3 .
all series 1,2,3 have interchangable parts not sure on the pre-series 1 fwd motors. and as far as i know (i could be wrong) but nothing is interchangable with the rwd motor. but the regal grand national motor is a good place to start looking for performance parts