While the V8 75's and ZT's may well be a desirable lot, lets not forget the V8 that graced the earlier Rover (And occasional MG) cars, the Buick designed (And disposed of because the Americans despised anything that was not heavy cast iron) V8 that graced many Police cars up to the late 80's.
Here is the engine in 3.9 liter twim plentum form