It don't seem to be rich at all.I don't even know what jets are in the carb(750 DP),but the carb,ignition,everything right down to the spark plugs are the ones that I used with the 377 I just pulled outta the car,and it didn't act like this!
I dunno if I'm even close on this,as it is only a guess(but at this point guess is all I can do,since this is the first time I've ran into this problem),but am I wrong to suspect a possible vacuum leak at the intake?I dont know if that'd turn the headers red,but I know the Vortecs are prone to intake sealing problems.