Holley PV Check Ball

[wvhylander]

I have a 850DP base plate I want replace with a 750DP base plate. The only difference is the check valve for the rear PV. 750 doesn't have one 850 does, Holley is closed can't ask them. What is the purpose of the check valve?

[wvhylander]

I was able to answer my own question. The check valve is a PV blow protector. You can purchase the kit to install one, but I don't know if I can install one in that elongated slot.

[1971ls6]

Plug the rear pv and jet it up