IMHO it depends on what kind of car you are running, I run a 64 Savoy in NSS, before moving east I ran the same car out west but was a points running bracket racer. Would I drop a GM engine in it, not a chance, just wouldn't be right. But if I was running a dragster, altered, or one of the super classes with a 74 Dart, it wouldn't bother be a bit to run a GM motor. it just makes financial sense if your a typical working man. Ten or fifteen years ago I wouldn't have said that. Just my humble opinion, Id look at it the same way if I had a street driver muscle car, Be it a Mopar, GM or Ford, Id keep the engine manufacturer the same as the car. Quick 16 dragster? Id be running what makes sense, dedicated race engine, manufactured by people who claim its a Chevy