You have forgotten the real scenario, most of these cars were beat like rented mules and the engine simply gave up due to over revving and abuse. I know mine was street raced with a vengeance and it is by no means an except. There was nothing "wrong" with the engines that would call for mass failure, they were just driven hard. If you take in account they all came with 3.55 or 3.91 gears, had 26 or so tall tires and half of them being automatic 60 MPH is 3000+ RPMs, do you think many people drove these cars 60 MPH when taking any amount of trip? The other half was 4 speeds and of course I know no one ever drove those aggressively or ever missed a shift. I would say if you look at any segment of muscle cars there are no more original engine cars in any line or model than in the AAR/TA cars for the above reasons, most just don't seek out a special block cause they were just blocks were as the TA block was a specific block, add to that that the TA block had a very limited available so a lot of the ones out there were service blocks or Duster blocks.

I think you ran across a pure coincidence and you are trying to add a back story to substantiate it. The back story is these motors got popped in a high number and a high number of people went to the troubled of finding a service TA block to put back in them. End of story.

On Jeff's sit there is a list of AAR VIN and SPD but not engine numbers info.

On the ordering question, so what I understood was correct, the majority of these cars were "factory spec" built cars just sent to the dealers. The part about turn to earn has been part of the car business since I have been in it even to today so not surprising that they were allocated by sales volume back then as well.