The importance of a torque plate

Very true, Chrysler was arguably the worst about it though. Other makes like Buick for instance had much better tolerances and QA/QC for mechanical parts. I get the cost aspect but there wasn't much of an excuse for the quality to be that low though especially when you look at how import manufacturers later came in and dominated with cars that were built really well but still affordable. But that's a whole other discussion lol they had completely different philosophies from the top-down on how to build things.

I guess my point was for the really high cost of using torque plates in a high-volume machining operation you could get similar or better results just tightening up already-existing tolerance specs on already-existing procedures which were pretty awful for Chrysler at that time.
I understand, on my 07 Mustang GT 500 the engine was put together by one man, had his signature on it. It can be done, for a cost. But $2800 Road Runners didn’t fit that bill then.