750 HPVS Tuning Question

[wcmachine]

I have a 750 HP vacuum secondary carburetor. If I disable the secondaries so it’s a two barrel, should I be reading 13-14 AFR at full throttle on just the two barrels? I’m getting around 15 AFR on the two barrels, but I’m getting 13.5 AFR on all four. I’m wondering if I should go up on the PVCR jets from the 71 I have now and down on the secondary main jets. Thanks.

[Gaz64]

You have 13.5 AFR when the carb functions as a 4 barrel.
The primary side is set to slightly lean side (15:1 AFR) to help with fuel economy.
The secondary side is slightly richer to even it up (12:1 AFR) to give you 13.5 AFR.
You could square it up a bit if you like, but fuel economy might suffer.
Typically, the primary main and PVCR should be approximately equal in area to the secondary main. Gary

[wcmachine]

Thank you. That’s what I figured, just needed some verification.