Big block chevy help!!!!!!
 

Hey Guys,
I have a fresh motor. Runs fine till it warms up then it starts to miss and pop thew the carb. Here is what I have. 73 454 std. bore speed pro popup pistons 10.2 comp. maybe. 750 holley with a proform main body comp cams solid lifter 294s cam with .595 lift. I lashed them at .022 cold. comp cams pro mag roller rockers and a old twisted eldelbrock intake. What would cause it to start poping and missing after it warms up? Also the heads are 781's from 73 does anyone know what cc of chambers they might have? Please help me!

It sounds like maybe you have an exhaust valve hanging up and not opening all the way and the left over exhaust leaves through the intake when it opens up. I had a rocker arm pop off of my bbc and the thing kept backfiring through the carb and it wouldnt even run.