I'm running a 212 hemi with a bp2 cam, 26lb spring , .020 over billet rod ,stock appearing carb and open exhaust. started running this at the end of last year with the stock tank and no fuel pump. Engine runs great for 3-5 laps then starts to break up and sometimes died completely. So, went to the track yesterday with fuel tank in the floor and fuel pump on the top plate. I had the same problem, Engine only would run 3-5 lap strong. What have i done wrong?