I have a PC Custom 750 Holley carb from a procharger kit. There is a fitting installed on the passenger front throttle shaft hole, and a groove machined into the underside of the base that would route the pressure signal to the other shaft bores.Can someone tell me why?

Thanks

To keep 4 drops of gasoline a year from leaking out the shafts onto your manifold. If you already have a carb. modified for pressurized throttle shafts hook up a boost referenced line and use it, but if you don't ,run it as it is.I used a new,stock 750 holley baseplate and don't have any shaft leakage worth dicking with.

Thank you, that makes sense.