Re: the 429 motor. There was a lot of high tech innovation going on for NASCAR, and some of it trickled down to street cars. The only negative I’ve heard about the 429 relates to air flow and the need for high RPMs for it to breathe properly.
As a teen some of us were on a Ford dealer’s lot at night after they were closed walking around, kicking tires and dreaming of muscle cars (and in full view of the street, nothing underhanded going on). There was a brand new bright red Ford Torino 429 Cobra Jet sitting in the parking lot with the keys in it. We never even cranked it, afraid if we were found sitting in it with the engine running we would be accused of trying to steal it.
The Chevy dealer was a few hundred yards away with a bunch of Chevelle SS396s lined up by the street, and the Plymouth dealer was a stone’s throw away with all the Road Runners and Barracudas lined up. Those were the days.