350 .060 over, flat pistons 4 valve reliefs, 62cc heads, 2.02 1.6 valves, .495/.510 246/254 duration @ .050 hyd flat tappet, roller rockers, dual plane intake, 800 cfm. I'm using 1 light spring and 1 medium spring in the distributor set @ 40 degrees. I have richened the power mode, and power staging mode of my car, also set spark plug gaps to .045. When I'm accelerating hard it pops, feels like a mis-fire or maybe a back fire, I have a mallory coil flame thrower module. I have racked my heads on this for the last year, I haven't put more than 10 hours on it since I built it. Pop has been there, I'm out of ideas. My vac at idle is about 5 in hg and it's not too steady, but I heard that's due to the long duration of the cam. Please help.