BBC 468 Procharger set up, MSD Pro Billett distributor, 6M-2L box, not using rev limiter.
Distributor - 2 light blue springs, stop bushing stock blue 21 degrees
I attempted timing on the water, but wasn't getting good readings so I went by feel. Last time I felt I had a good timing reading it was at a total of 34 degrees. Rotated until it backfires, go other way till engine rpm comes up and smooths out, then just a little more for safety (I think this is for safety)
My backfire happens when coming off throttle at the point where I'm feathering the throttle. Always a single pop that worries me. This set up has never idled very well for me so I have to feather the throttle. I'm able to keep the backfire from happening all the time, but it does happen and I want to stop it. If I run at a steady 2000 rpm no issue. Same at a steady 3000 rpm. Wide open runs very well.
I was thinking my advance curve may not be ideal. Should I go with both light silver springs for quickest advance? How about the stop bushing, if I allow more advance curve then at low rpm the timing will be later than it is now. I think I'm thinking in the right direction. If I'm going the wrong way straighten me out.