High altitude adjustments

[cwhubb]

I need a little help from the nose bleed racers out there, I live @ 6300ft elevation and the nearest track is @ 5000ft give or take, I have a holley 950 hp, what size jets are you guys running? also should I adjust the air bleeds and pump shot or just stick with the jetting? My set up is a .30 10:5:1 440, heads flow in the 280cfm range, rpm performer dual plane,

1 3/4 headers into a full length 3 inch exhaust, Dana 60 410 gears, 25.7 diameter tires, 3500 stall manual shift b&m 727 4000lb car

 

[moparmarks]

I'm at 4700' and in my 72 Satellite with a mostly stock 77 truck 440 I'm running 67 in front and 72 in back. This on a later version of the 3310 750cfm. Could still go to 65's in front. This is on a street driver.
I would start with 72 on the primaries and 76 in back to start with. Run it and then read the exhaust and plugs.

 

[67Satty]

Don't forget you can run more timing at higher altitude too. I race at 1,500 feet. Doesn't sound like much but the density altitude can be as high as 4,000 feet.

 

[cwhubb]

Good starting points thanks, are the air/fuel gauges worth a darn?

 

[cwhubb]

checked the old 750 carb and it had #63 jets, that carb ran well