[Jack21]

If you're going to continue to tinker with the Holley, replace the secondary idle adjustment screw with one that can be adjusted on the car whth the engine running (idling) with an allen screw adjuster. You want to see both the primary, and secondary idle transfer slots as small squares above the butterflies (.020" - .035"). It is preferable if you have idle richness mixture screws to adjust on both primary, and secondary side. If not, purchase secondary metering block that allows richness mixture to be adjusted.

One would think that after 50 years of dealing with these issues that Holley would have sorted this all out. Well, sorry to say they haven't, but Barry Grant has.

If your cam has over 220 deg intake duration @.050, replace your Holley with a Demon. (!!!) As one of the huddling, and unwashed masses who had given up all hope, I sprung for the Demon to repalce the Holley. All I can saay is "Holy Sh!t, I don't believe this!" The car has a real motor in it!

No, I don't work for Barry Grant, or Holley...but! In a recent engine build up mag, all the Holleys were replaced by Demons for their dyno floggings. Chevy, Ford, Buick, Pontiac, Olds...all dyno'd with Demons instead of tried and true Holleys?

I couldn't believe the difference in drivability, and you won't either. I'm still downjetting and plug reading from out-of-the- box, to get the best A/F for street driving, but the responsiveness between the Holley, and Demon must be felt to be appreciated.