I put a new comp 292 cam in my 460. The cam dowl was at 6 o'clock my crank gesr, keyway and dot was at 12 o'clock. I put cylinder 1 at TDC. And dropped the distributor in facing the driver side firewall and all the plugs are in the correct order. She starts and runs like ****. Then blows and backfired through the carb and exhaust. Please help

 

As you turn the motor and the #1 piston approaches TDC watch the valves. The intake should be opening at or just after TDC. Keep turning it; intake should close and then it should come back to TDC with both valves closed. While it is at this "second" TDC the rotor should be pointing to the #1 spark plug wire. This will get your timing close enough to start. Make sure the firing order is correct.

Also make sure your valves are adjusted correctly, if you have them too tight it will hold the valve open; too loose and they won't open enough for the motor to breathe correctly.

 

cough-up through the carb= cam/crank out of time; fire up through the carb= ignition out of time

 

Did you check push rod length ? How much lifter preload do you have ?