Setup for 750DP on this 408
Air bleeds are used to correct the fuel curve. Generally you shouldn't have to mess with them too much, if at all.
More important, especially on a Holley 4150 and similar, is the transition slot - which acts as a variable airbleed and a fuel restriction. If its not set within the design range at idle, then the off-idle mixture will be too rich, or too lean (more common) and too slow. On an older traditional Holley - like a 4779 - the working range at idle is .020 to .040" showing beneath the primary throttle blades at idle.
Many newer cabs may have a tighter range. Definately will if the slots are long or wide. Some are so long or wide that its worth the effort to shorten the slot! I don't think you'll see a need to do that with a 4779, even a newer one.
Air bleeds are used to correct the fuel curve. Generally you shouldn't have to mess with them too much, if at all.
More important, especially on a Holley 4150 and similar, is the transition slot - which acts as a variable airbleed and a fuel restriction. If its not set within the design range at idle, then the off-idle mixture will be too rich, or too lean (more common) and too slow. On an older traditional Holley - like a 4779 - the working range at idle is .020 to .040" showing beneath the primary throttle blades at idle.
Many newer cabs may have a tighter range. Definately will if the slots are long or wide. Some are so long or wide that its worth the effort to shorten the slot! I don't think you'll see a need to do that with a 4779, even a newer one.