Holley running rich at part throttle cruise

evil66 said
Carb is later than a 4779, its a 750hp with adj air bleeds. I had a 4779 on it originally.

The hole originally was at low to mid speed crusing and give it a quick stab on throttle, seems much better with the 10.5" pv over the 6.5".

Wide open throttle was always good with the 74/82 jets and 6.5" pv however it was running a bit rich cruising around, so i would like to end up with the same total fuel at wot with better driveability and leaner cruise.

Havent done much wot testing with the leaner primary jets, i want to get the pvcr channels drillled and tapped so i can increase the total fuel back to total of 74 jets plus pv with the leaner main jets and bigger pvcr channels.

The newer carbs can be goofy. Maybe you've discussed this with YR in PMs. Extra and too much e-bleeds, kill bleeds in the wrong location, long t-slots are some of the main offenders. That all said just as a caution. In general to get the idle rich enough to be decent at relatively low vacuum and not have off-idle and low speed cruise rich takes some work.
Lets say its 8"Hg of vacuum at 800 rpm and 14"Hg at 1200 rpm in gear. That's a big change in pressure on the idle - so lots more fuel will flow even if the amount of transfer slot hadn't changed with throttle opening. For example when coasting.

Having the hole in low to mid speed is tricky to evaluate because the main system is starting to contribute fuel during part throttle acceleration. If its not happening at all at highway part throttle then its the transition off of transfer/idle or the quality of initiation of the main system.
Idle system normally will continue supplying at higher rpm/deeper throttle by using a little larger IFR. To keep the ratio similar the IAB will have to increased at the same time.
Initiation of the main system can be effected by those items mentioned sometimes 'goofy' on new carbs. Also by main airbleed being too large or too small. But the main job of the main airbleed is to correct AFR so it remains consistant through high rpm. So I like to know how that is working before change MAB. Guys with more experience can use that knowledge to jump ahead based on their knowledge of how many combinations have worked out in the past. Sometimes they can go to something similar in their notebooks.