Hypothetical Six Pack

By 75, insurance co, emissions, gas crunch? ,and high performance cars were not in vogue pretty much. The 69 1/2 M code B bodies had aluminum intakes, and supposedly, Mopar was having trouble getting what they need, so they cast their own in cast iron in 70 if I remember how the stories go. Yes cast iron one were very heavy.
I have had quite a few 440-6 original cars decades ago. Cool eye candy, but a good 4 bbl will run right with it or better. Easier to tune. Sorta like the hemi, a good 440 will keep up or better if the hemi is not tuned well. Just the nature of dual carb anything.
I had a number of AAR and TA's back in late 80 early 70's, A great handling package, but even better in an A body IMHO... lighter, yes even better made car. E bodies were not very light.