Part throttle bog then backfire?
Krazy, I'm experiencing a slight part throttle bog as well, my distributor has an aggressive curve. Do you know which color springs you have set up?
I used the stock electronic distributor "light" spring (the one that comes with the carb new in the box) and then one of the two light recurve springs you get in the Mopar Performance plastic baggy.
The two light springs from the mopar performance baggy were too light when I used them together and I was using up part of the advance at idle. Recurving is a "balancing act". You need a spring combination that does not allow any advance while your engine is at idle, but then advances just off idle. If you have a big cam and higher than stock idle, you need a little stiffer spring so you don't advance while idling.
The stock distributor "stiff" spring does not kick in until later, that's why it has a big loop on one end. Throw that sucker out. Use two light springs.
Some of the springs do not have any color paint on them.
If you have a pile of distributors around, take the light springs out and measure the spring wire daimeter with dial calipers or digital calipers and find the wire diameter and then count the number of turns in the coil. The smaller wire will be lighter. More coils will also be lighter than less coils.
After setting up the distributor, put it in the car and start it. Then get an advance timing light and tuning tach and map the curve for each combination from idle to full advance. Then drive each combination and see how it acts. Use the best running combo for your engine. It's trial and error... Hopefully not so much error....
