ATOMonkey

That's the question. I know I'm running rich, and I have jets, I just don't know which ones to put in.

__________________
'89 Red Formula 350- '74 4 bolt 350 .060 over w/ forged pistons, XE 280 flat hydro cam, Performer RPM, Holley 750 DP, Vortec ported 1.94 1.50 heads, ZZ4 HEI ign, Hedman shorty headers, Single 3" Exhaust, WS6 suspension, 9 Bolt 3.27 Posi, Edelbrock LCA's & Track bar, subframe connectors, 700R4 w/Borg Warner internals and Dacco 2500 stall converter, A&A snorkel scoop, Eclipse Head Unit, Delco Bose Speakers, 2 8" Optimus subs in B pillar w/ 400 watt/chanel amp
Best 1320: 13.7@99 mph

Superman

Holleys all came with different size jets. The only way to find out what the stock jetting on your carb is supposed to be is to get the numbers of the coke horn. If you post the numbers I will tell you what size the stock jetting was in it. Or you could start backing down two jet sizes at a time till the engine stumbles then got back up a size.

ATOMonkey

Cool, I'll check it out tonight.

F-BIRD'88

Try 70 primary and 80 sec (without sec. power valve)
or 76 (with sec power valve)

This is normal jetting for a 750 DP carb.

Be sure your "rich mixture" is not in the idle circuit which has nothing to do with the main jets.
Check that your power valve has a vacuum rating that will alow it to remain closed at idle. (in gear).

five7kid

Get the Holley jet assortment kit from Summit or Jegs - about $35. It will have a pair of everything from 66 to 99 (I think that's the range, anyway). Then, when you pull the bowl off, look what's in there, get a set 2 below that (as stated above), and go from there.

The assortment kit will cost you less than buying jets in pairs by the time you find your right ratio. And, you'll never have to buy another jet.

__________________
See detail on my cars in My vBGarage

I'm a racing fool. Not necessarily in that order.

ATOMonkey

Thanks for the help. I finally bought my daily driver ('88 Turbo Coupe), so I can start tearing into the beast. I'm going to port/polish the heads since they are in desperate need of it and then see how she goes. I was runnig Friday night and the temp probably got down to high 60s F. The cooler it got the better she ran. By the time I parked it it was running 5 in. Hg. more vacuum at idle than usual. I'll have to check on that power valve vacuum thing. Also I have another question. I can't seem to get it to idle down when I have the vacuum advance on the dist. connected. It idles around 1000. The throttle screw isn't touching the linkage, and I have the idle circuit adjusted right. The linkage isn't sticking either. I was wondering if anyone else had these problems. Like I said though, I'm going to be tearing into it, so this might all go away when I put it back together. All I have to do now is shell out $90 for an electric grinder. Stupid compressor isn't big enough.

ATOMonkey

Here's the numbers that were stamped on my choke air horn

4779-8

2920

Superman

71 primary-80 secondary