Darn, another edelbrock cam set up that pops through the carb. Check your valves with the engine running and covers off. Make sure your getting oil to each of your rockers. If not you might have the same problem as a friend of mine had. He had a bad lifter, his wasn't getting oil to #2 exhaust, figure the lifter was just collasping and not opening the valve properly. Take a look at that. IF that's your problem I will know that edelbrock sent out a bad batch of lifters.