Hey guys I have an issue with once I hit 6k my engine pops, starts breaking up through exhaust. I'm running a 347 roller motor with the F 303cam, windor Jr heads, 1.7 comp cam roller rockers. I would imagine a 347 stroker with this cam and rocker arms should spin well over 6k easily with no issues? I'm running a 650 holley double pumper and it's not running too rich at all, plugs are burning perfectly tan. Any one have experience with the Fcam? It almost sounds like the valves might be floating at 6k which once again, with those heads and rocker arms I don't understand why they would float at that rpm. I hear of guys that spin their 347 stroker all the way to 7k. This engine is fairly new to me, I didn't build it and just bought the car last October.