Are 58 main jets the correct ones as delivered from Holley? Or are all jets to Holley spec? That is the best place to start tuning.
Does that carb have 4 idle screws, 2 in the primary and 2 more in secondary.
The stock sizes for this carb are 65/72 but I swapped them down to 58/65 to raise the cruise AFR from 9-10 to its current 13. They are actual holley brand jets if that was your concern. It has 2 idle screws. I rebuilt this carb to spec with all new parts. Throttle plates adjusted to spec (transition slots square). Other than the primary jet size and idle screws, it's all spec.
I stayed up till 4am reading last night and have created a list of things to check today:
- PCV functioning? (it's brand new but cheap so who knows) - Float bowls (confirm height after its been apart a few times) - Accelerator pump tight (was tight but have been changing jets and PV so better double check) - Secondaries opening smoothly? - Consider inserting narrow Wire in idle circuit to lean the mix - what is Vacuum during hill climb (should be PV size)
