power valve size

Yes and no, I see where you getting your ref from, so now the power valve is still the same It opens at 10.5" vacuum so you have 6 " at idle the PV's are open, and it will run overly rich. I just talked to a buddy of mine that runs a lot of blower motors on the street and he is running 2 950 80577s and Holley told him to block the power valves. Hmm than why are they there? I guess I would have to pull the bowl and metering block and see if the port on the side that goes to the manifold is just over riding the port in the base plate for a vacuum signal or the one in the base is blocked. Ether way when the manifold is under pressure the PV is open and closed under vacuum so were still at the same point your PV is too big for the vacuum you have at idle.