[DMT]

Double check to make for absolute certain that the plug wires are on the correct plugs.

If that checks out make sure that you did or didn't purchase a 4/7 swap cam. If you did you may have the number 4 and number 7 plug wire mixed up?

You didn't say what kind of heads you have so IF they have pressed in studs then with that kind of lift, the spring pressure needed to control that lift will pull out the pressed in studs. The reason I mentioned this is because you wrote that you have a roller cam and what you are describing sounds like a flat tappet cam with a wiped out lobe. It can't be that being that you are running a roller cam that's why I thought about checking this for a valve not opening and closing. Popping thru the carb is more likely an ex. valve not opening if this is the problem?

Another area to check is if you distributor cap is on all the way and not at an angle which can reek havoc on your spark timing. Also check to make sure your wires aren't causing any cross firing, if you read this tonight that would be easy in the dark by looking at the engine running with no lights on you might be able to see the spark jumping. This still could be the problem if you can't see it with the lights off at night because the spark could be jumping a very small gap shielded by something. Make sure the wires aren't bunched up where they connect to the dis. and if you have wire looms make sure the wires aren't arching there as well. GL



Derek