The plugged power valves are a common drag race thing also. The power valve is there to add fuel when needed. A race carb is running at wide open throttle all the time anyway, so just jet it accordingly. The rear power valve also gets uncovered just like the jets do, but no way to extend it. When running a pv plug you jet up by 8-10 jet sizes. It will run very rich putting around the pits, but will run good on the track.

For a baseline on the carb: With pv plugs: jet it around 84-85 on all 4 corners, 35 or 37 squirters to start, may need bigger if no transbrake. Biggest pump cam you have.

Later,

You can put the pv 's back in. I would put them both front and rear. Running pv's will be be around 8 sizes smaller on the jetting. Jet it around 76-77 to start. You may need to go up or down a size or two after looking at the plugs. Leave the jet extensions on. I would leave the squirters alone to begin with. With that cam I would think that you will need about a 4.5 pv.

later,

Coat the gaskets with "Pam" cooking spray and they will still seal, but will come off without sticking. Also been told that chapstick works well too.

You shouldn't have to change jets that often once you find the setup. Since it's a street car you might want to have a summer setup (leaner) and a winter (richer). Once you find the right power valve you won't have to mess with it. I based the 4.5 on the fact that I run a 3.5 with a little bigger cam in my 383W stroker. It's also a solid roller, .624/.630, 262/272 @ .050. I pick the pv by the vac the engine pulls at idle in gear. Take the vac, subtract 1 for fluctuations due to rough idle, then divide by 2, round to the low side. Mine pulled 9" vac. Subtract 1, divide the 8 by 2, got 4, round down to 3.5, since pv's come 3.5,4.5, etc.

Later,

David Cole

The 35 and 37 squirters should be a good starting point.

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'85 Capri
Cleveland powered
carburetted

'72 Pinto
CARBURETTED,draw thru turbo 4 cylinder. Runs good.
http://pub43.ezboard.com/blowdollardragracersassociation

Most of the 850's come from Holley with 80's all around and 2 power valves. I do think that some of the newer list numbers might come with 78's in the secondarys. The 4781-2 that MrXerox has came with 80 and 80 with both power valves. I can't imagine going with 4 or 6 sizes smaller unless you were using a very small intake and was getting too much booster signal at high RPM's. I ran an xcellerator for a while,and 80's worked best for it. 81's worked best for both my portosonic,and strip dominator.

I am currently using a 4010 series 750. With the correct spacer height combination I am running nearly as good as the 850,with a lot better driveability in the pits. Once this season starts and I get to play around with it a little more,I am confident that it will deliver as good or better performance. I was glad that Holley came out with this carb. Almost like the Autolite 4100,only with a CFM rating closer to what I need,although I do have one of the rare Autolites with the 1.19 venturies. These came with Holley jets which makes things a lot easier. They were only around 600 CFM though,still a little small. I only went 1 1/2 tenths slower with this carb though. Its too bad that the 4010 series didn't take off. They suffered from a lack of understanding I think. One good thing though,everyone thinks that they are junk. I have three of these now and the most that I have paid for any of them is $50. Their loss is my gain.

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'85 Capri
Cleveland powered
carburetted

'72 Pinto
CARBURETTED,draw thru turbo 4 cylinder. Runs good.