Watched that last night. Good program.
Amazing that the engine upgrade was often 25% of the cost of the car. And in the case of the Chrysler 426, came with no warranty.
My aunt bought a 71 Buick Skylark GS Stage I in '73. It still had the 455 Stage I engine with big valves, ported heads, and heavy valve springs. But the aluminum rear end had been replaced by a standard 10 bolt GM rear end.
She used it as an escort car through the 70's for mobile home transporters.
