mopowers
Well-Known Member
Does anyone happen to know off hand what the stock PVCR size for a 4779 (750dp) Holley is?
4779 is there a - # after
4779 and 4779-1 have 8.5
4779-2 through 4779-9 have 6.5
Mike's working on one right now. He's got the specs of what he found in it posted
Holley - racingfuelsystems.myfunforum.org
Funny I have long term loaner 4778 here with the choke tower cut off and the body restamped 4779-2. But the venturi measurements can not be denied. LOL
Send me an PM with your email.
I have a spreadsheet to help figure out the total area of jets/PVCR.
You can sort of figure out the PVCR sizing if the rear doesn't have a PV. The jet spread area sizing should be very close to the PVCR sizing.
Every .004 increase is equal to approx 1 jet number, .059, .063, .067 etc. Don't be surprised if you need to go up to .063 or .067 I always end up dropping primary jet size to lean primary cruise and then dial in WOT with the PVCR up front and SJ.Well, I opened up the PVCRs in front from .055" to .059". I'll take it for a spin today to see how it responds. Hopefully the .004" isn't too large of an increase.
Every .004 increase is equal to approx 1 jet number, .059, .063, .067 etc. Don't be surprised if you need to go up to .063 or .067 I always end up dropping primary jet size to lean primary cruise and then dial in WOT with the PVCR up front and SJ.