Pvcr's
 

Is there a way to accurately figure out pvcr size if I know 7 lbs of boost with .062 pvcr's gives me a afr of around 10.5,I want to double my boost but not sure about the correct size of pvcr to be close to a safe afr.my metering blocks are drilled with a 6/32 thread and can't get much more of a jet size in these things.figuring I need to drill and tap another set in these metering blocks,and i need to know what size the new pvcr's need to be.I'm thinking another set of .062's.maybe I'm wrong.somebody clear this up for me.going to the track soon for some test n tuning.

I dont think that there is a perfect way of doing that.

I can tell you that my 4cyl had .070 front jets with .076 PVCR'S. Rear was .088 jets @ 5psi and 11.80 AFR. I have drilled the 6/32"s to .086 . You will drill most of the allen flats out but i was able to pull the tool to the side and get it in and out.
At 15psi it had .072's with .078's PVCR's front .092 rear jets.

Also i had aluminum head with 25 dgrees of timing.. At 15 psi i was making 525hp.

Maybe this can help maybe not . Sorry i dont have an 8cyl. lol Its a comparison for you in away ..

Even in the late 1960s and early/mid 70s the Holley Engineers used High Tech Gas Analyser Equipment to dial those circuits in on a carburetor.

I still have my old Horiba Gas Analyser equipment but some of the new stuff works almost as well and costs 1/10th of the cost of the Horiba I used.

Most 850 carbs were calibrated with a .059 PVCR for each barrel.

When you go boosted, then most try to keep the jetting on the Primary close to stock and up the fuel flow under boost with the primary PVCRS and large secondary jetting.
Some do large primary and Secondary PVCRS.

A Trial and Error deal. Buy a good Exhaust Gas Oxygen Sensor (or two of them) and learb how to read and understand what the engine is trying to tell you.

Tom V.