I guess I look at part of the reason for the cycle of, "there are no high hp cars at the track/there are limited choices for high hp mopar parts" is this:
If you're looking to build a high hp motor for your chassis drag car/dragster, etc...... And you're not brand loyal to anything in particular, just want a reliable cost effective motor, that won't take a year to build....... After you look at all your viable options...... The cost and lack of comparably priced hard parts...... The decision is more or less made for you...... And it's not Mopar.
99% of the guys building high hp Mopar combos are die hards...... And there's just less and less of those around.

I remember being at New England Dragway at a test and tune quite a few years ago.
This girl was driving the family dragster making lap after lap trying to nail down the reaction times and get consistent ET's for the upcoming(at the time) IHRA national event where they were going to be running Top Dragster.

Single carb, no tow vehicle, mufflers, big chief heads, probably like a 632....... Just running 7.5x run after run.
I thought to myself......"pretty hard to argue with that".