Originally Posted by T-bucket23
Pull #1 plug, put finger over hole and have someone just bump the key until you feel pressure pushing your finger off the plug hole, bring up the timing mark by hand and check the distributor rotor to be sure it is pointing at the #1 plug tower. If not you will need to remove and reset the distributor.
You didnt say what you have done so far, there are lots of other possibilities but this is the most common mistake made when putting an engine back together. The other issue that could cause backfiring through the carburetor is tight valves.
I will do this tomorrow to check. So when the pressure pushes the finger off, that's compression getting raised, correct?
Back fire is coming through the exhaust; exhaust isn't hooked up after the headers, so it's very obvious when it backfires and that it's coming from the exhaust.
As far as mods, I have aluminum heads with roller rockers. I don't have specs on things since I got everything when I got the car, and it was already all torn down to the block/internals. Just got it all checked out, and got it altogether.