Ok yesterday i installed my new fuel pump im still having the same problem it sumbles at all speeds and in every gear? I have an edelbrock 1406 600 cfm carb and i went as far as checking the cap and rotor and they were bad i need to do plug wires and im installing a new coil too......Ok i checked the vacumm advance its was hooked up wrong it was to a constant port i thought it should be to a ported vac switch so when you give it gas it will then advance the timing?? Ok i checked timing with the vac advance disconected and on my timing tab there is a metal tab with a circle and a pointer there about 3 inches apart anyways the timing mark was at the pointer is that correct or is the timing way off??? Oh yeah on an edelbrock carb what is the max fuel presure you can run? my pump is rated for 6 psi and 120 gallons per hr....i hope i can find this stumble..miss what every it is...because its VERY ANNOYING you get drive the car comfortable at all....you have to be on the gas all the time to not make this stumble....HELP....