I know there are lots of threads on this topic. but none seam to be able to help with my problem. I recently rebuilt my motor. now running 135 lbs compression across the board. i am running a carter bbd 2 barrel carb a pace setter header. ngk v power plugs. one step hotter than stock. (the burn on the plugs looks pretty good if any thing a little on the lean side) right now the timing is advanced as far as the distributor will allow. and i have managed to minimize the dieseling. but still on occasion it will diesel. I am currently running the distributor that has 2 stages of advance. but only have one stage hooked up. (the bottom stage) to a port on the upper side of the carb that has vacuum when above idle but nothing at idle. i do not know what rpm my idle is at but i know its pretty low. ( ac pump all but kills the motor at idle) I have tried to retard the timing and that only made it worse. also i have eliminated all vacuum except the advance. and running an electric fuel pump with about 4 psi pressure. with no return on the carb to the tank. I am currently getting about 22-23.5 mpg and thats running 75-80 on the freeway. and 35 around town about a 50-50 split on a tank of highway and city driving.
so my questions are any suggestions on the dieseling issue.
2. what mpg does every one get.
3. if i were to add a return to the carb (drill and tap a port) would i want to regulate on the return side, or the inlet side and does the 2.5 psi every one has posted really work?