[Project Nova]

I cant find my original thread,but i was having major backfiring at wide open throttle. I trouble shooted several suggestions but still have the problem.Even changed the Edelbrock 600 with a Holley 650. Now im thinking its the adjustable vacumm advance. Could anybody give me some idea how to adjust this as i've not done it before. I know it requires allen wrench into the module for adjusting, but thats all I know.

 

[74 hatchback]

I had backfire issues with a adjustable advance years ago, now i dont use one. Just set initial timming to 16 and put soft mech advance springs in and see if it goes away.

 

[novaBRO]

disconnect the vac. advance and see if it goes away