[GRX]

Great subject. Almost wish cell phone videos were as ubiquitous back then as now. Almost.

Back in the day one of the baddest street racer cars around here was my neighbor's 390 powered AMC javelin. Remember him spanking a lot of cars with it. Including some BBC cars and Pontiacs.

As said above, a large part of it was tuning. Another big one is production inconsistencies. How much casting shift? How closely did quality control monitor the machines? When blueprinting you can see how many variances there are. Of the muscle car era engines I have worked with Mopars were the worst offenders. Valve spring seat depths all over the place. Conn rods several grams off from each other. Indexing and stroke specs on some of the cranks was atrocious. Essentially had to 'unlock' the machine and align it with what was already there because fixing would take it far below bearing under-sizes. This is why you could have one Mopar that ran like a scalded dog, and another like a sick puppy. Same deal goes for other brands as well. Our Pontiacs included. Just not bad as others.