I'm running too lean.. I'm getting an exhaust backfire when I turn it off and my plugs are whiteish... It only happened every once and awhile, but I just installed an edelbrock performer intake and I think now that its flowing better, its worse... The car is an '85 TA, L69 stock carb (DR rods ?? hanger) with hooker catback, gutted cat, march pulleys and roller rockers... Timing is *7 BTDC.. I was running *9 and backed it down but it didn't help. I also have new cap, roter, plugs (gapped to 45) and wires.... Do I need richer rods, hangers???

I'm going to dyno this weekend so want to get this corrected first...

THANKS!!!

 

The rods and hanger won't affect a lean idle (backfire when shutting off). Whitish plugs are what you want.

As for flow improvement, I did all my mods in one shot, and I did the following adjustments when I first started it up (compared to where things were when I shut it off stock to do the mods): Idle speed, choke idle speed, choke pull-off. That's it. I'm sure I improved flow over stock with what I did a lot more than what you did. Yes, I'm at a higher altitude, but that shouldn't make that much difference.

Check for vacuum leaks, if you think it truly is lean. With a manifold change, that's your most likely culprit.