Sorry Pontiac here..... come on folks we all know what we get when we pick something just to be loyal we dont always end up with the best option. I was a loyal sucker to mopar in the 80-s for a daily driver but still had a 5.0 and GN to go fast with.
Late 80's I had me a my first Diplomat AHB. Honestly wasn't bad with the factory Police 318-4 with the 360 heads and a quadrajet once the converters were removed along with the air pump. Not a race car but very enjoyable car to drive, and RWD, V8 Mopar with solid rear axle and t-bar suspension unlike most things they made then. Eventually it got one of their crate 360/300hp engines rated at 375lb/ft torque (but dynos showed more) and man that car would move with a 3.21 sure grip rear. I have another '89 AHB now with 408 and 3.21 rear and sure grip and is an absolute blast.