Headers turning bright red, not idling.

It's been established my vac. advance distributor even while unplugged still advances is a problem, but I don't think it's causing these. I've tried 2 different carbs and 110 octane but nothing seems to do the trick. I had similar problems on the last engine and they just seemed to go away after the cam was broken-in but it was also overheating last time and it isn't now. My friend says the cam's a tooth off, I say maybe intake leak.

Any ideas? Here's the motor:

355, 256/263@.050 solid cam, victor jr. intake., holley 750, sportsman 2's.

 

check your timing, make sure est is disabled when you set it and it advances or retards correctly, you have retard box on it? if so check it out

 

est is disabled? The distributor isn't computer-controlled if that's what you mean.