Exactly.
Now mind you, most people will start off with a naturally light weight car by design such as a Colt or Cricket, but some if not most of the time, starting with a bigger heavier car gives you many options to distribute weight throughout the chassis for some control. And I'm not even mentioning wheelbase yet.
If I were into those rockets, of course naturally it would be fantastic to stuff the biggest engine package and go racing, but strangely enough I probably would choose a 360 small block which in doing so would make the car even lighter, but not all in one place.
A big block and or a Hemi probably made those cars so nose heavy that once it gets drunk out on the track, it becomes a boomerang tossed in all directions.
I saw many a Starlets, RX3's, and even Pinto's with Rotary 12's and 13's go dizzy on the street. Of course, they were all sticks.
The most stable cars I ever saw were Electra 225's and 66' Chevelles in lightweight form, but with some wheelbase real estate to stabilize the whole package.