holley carb help,transition/stage

scampy said

This is kinda what I had in mind, drop the iab down, your thinking that much from apprx .072 to .067, of course idk is that even alot for iab. Will this change anything timing wise with the mains coming in? or just swap those iab in front only and retrim the idle mix screws. No issue with having different iabs front to rear?

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Changing the IABs will not change the primary circuit timing coming in. Going smaller on the IAB will extend and enrich the idle circuit.
When you change the IAB size you need to readjust the idle mixture screws.
I suggested changing the front only since you did not know the size of the rear IFR. The car is running mainly on the front idle circuit on the return road, the rear idle is supplying some fuel but most is coming through the front transition slot.
On my Proform 750DP I run .035 IFR bottom position, .067 IAB, at 3/4 turn all 4 corners, .020 transition slots and it works great for me at sea level.
An easy way to check if the Idle circuit is good is to slowly rev the rpms up in neutral until till the mains come in. If it starts to misfire you are to lean.