Buick GSX and Plymouth GTX

Oldsmobile was no stranger to the Hemi concept, either.

http://www.carcraft.com/techarticles/ccrp_1101_oldsmobile_hemi_engine/

The only thing I never liked about the Olds engines was the chinsy rocker arm hardware. They just never had camshaft profiles hot enough that warranted an adjustable valve train. They still had some nice cars though. If you wanted some muscle with some luxury thrown in, the Buick or Olds fit the bill nicely. Anybody couldda had a Chevy. And far as I'm concerned, Pontiac doesn't even enter into the equation.