You would be wise to check with your local division tech guy about what they currently rate the 1971 340 motors in the A bodies compared to what they rate the 1970 340 with the AVS in NHRA stock, same deal on the 1972 and 1973 340 thermoquad motors scope
I use to race in NHRA stock, a good friend of mine set E/SA record in his 1971 340 Demon at 10.89 that stood for two years before NHRA put it back to a minimum shruggy
NHRA can be very political, all the Chevy racers in his class griped and cried and file protest on him until NHRA refactor his combination up to 305 HP puke
He built a new car, 1970 Challenger T/A clone and set the record in it also, they ended up refactoring that combination to 315 HP in the T/A Challengers, the 340 6 pack AAR didn't get hit at all shruggy work
He finally quit NHRA racing and got into Jeeps and off roading realcrazy

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)