This photo is circa 1969; for the purposes of this discussion you may disregard the '65 GTO (which I also still have).
K[/QUOTE]I have a hard time disreguarding a 65 GTO, I had one! Loved it, quite a stroy about that car. Came (to me) as a 389 4 speed, and I found an SD421 in perfect low mileage condition out of a Super Tempest that had been wrapped around a new Mexico Pine tree about 5K miles after it was driven off the lot. My GTO was in great shape too, owned by an older guy who in (1976) just wanted to get rid of it for something with better mileage and get out from under what he named the GTO, my little ticket machine!
I stuck the SD421 in it and put in a Borg Warner Power Brute clutch and the thing was super fast. I was sitting at a stop sign one day, the clutch had such a hard pedal my leg would start shaking if I was stopped for more than about ten seconds, and I was just about to take off when a large almost pop scared the crap out of me and the headliner was smoking! I had no way to move the car because when the pop happened it stalled.
Turns out the clutch blew and grenaded itself and the reason the headliner was smoking is part of it, a piece about the size of a slice of pizza, was lodged in my ceiling! After retracing the path, it missed my left cheek by about a quarter inch, then I remembered something hot screming by my face.....
I got rid of it but sure wish I still had it.