Mikey, I agree about the radiator swelling under extreme heat, but that did not happen to this 'vette. It just melted the plastic fan shroud enough to stop the electric cooling fan.
I wish that dyno operator lived here. I can't trust the two dyno shops around here at all. One installed the wrong spark plugs, spark plug wires that were not in holders, and burning on the headers, and metering rods in the carb's, that was $900.00's and called it good. The other one, claimed it was smoking out of the tail pipes, and pinging under a heavy load. They also advanced the timing another 2 degrees to 38. It does neither
They wanted to pull the cylinder heads, to check the quench, and by the way, the compression test, and leak down was identical in all 8 cylinders. I think they saw a cash cow..........Not. This was another $580.00