ok so i got my truck running...(thank god)chev 350 edelbrock intake holley 570 cfm carb. anyways it runs great but i have a stumble off the line. It goes away when the secondaries open and seems to be quite resposive at higher rpm but off the line nothing. I have played with the fuel to air mix.getting the most vacume at the intake.timing is set to 12, have tried at 14,10,8,same. Float levels are good. could it be the pump shot or accel pump on the carb. i get a steady shot of fuel out of the pump shot. could it not be enough or to much? how do you tell?