1994 Chevy Camaro Misefiring Banckfire

Engine Performance problem
1994 Chevy Camaro Two Wheel Drive Manual 115000 miles

So I am helping a Friend who is looking to sell his car. It is a 94 Camaro Z28 with hot cams. Right now I have a list of things that need fixing. Anyways. The car starts and runs fine when the engine is cool. If i push the engine it occasionally misses and as the engine heats up the problem get worse. When the engine heats up to about 210 it gets really bad. The engine starts to misfire and backfire. It gets to the point where I cant even Idle in first gear. If I idle the car at this point it misses and backfires.

I park the car after it does this, when I turn the engine off the temp gauge goes up another 20 degrees or so. As soon as I run the engine again the temp drops. (or so the temperature gauge indicates). I have replace the coil. Flushed the coolant system. I was wondering if the car would run like it is because of the temp or if there was some other problem independent from the cooling problem.