Most people that do swaps (me included) just look at cars/trucks as a “shell”. You find the “shell” you like most or works best and install whatever “powerplant/drivetrain” that you like best or works best. For example foxbody mustang with a LS engine is basically one of if not THE best drag car out there with minimal effort. The worlds fastest fords tend to be GM powered....and thats a fact. I run a bone stock LS in my ‘49 just because it wasnt worth fixing the stock engine for what i wanted/needed. Was the stock motor ok when new? Sure was....BUT your not gonna be able to do half the things you can do with the newer powerplants. I get your stance somewhat on the “keeping it as it should be” style. I actually built my GMC around that stance but with a hidden LS hahaha. If the average joe looked at it they wouldn’t kno anything was ever done to it. At least its still all GM 👍