Holley 23XX Series Modular Carb Stuff

The list 07448 version as previously suggested, comes with size 61 jets, which are ideal from sea level up to 3000 feet. The early versions like the "parts is parts" special that's presently giving you fits, came with smaller jets, but you really can't compare jet sizing between the old versus the new in a strict, apples to apples fashion. The internal calibration is vastly different between the two.
 
The 350 cfm 2bbl Holley 2300 will come with probably the #61 main jets. The higher air flow capability requires the larger main jets to retain the correct air-fuel ratio. With the ethanol additive, you May find the #62 or #63 main jets give better performance. Don't lose the smaller jets as they will be needed for higher elevation operation = +5000ft.
I have the #62 mains in the 350cfm carb and am at +80 ft elevation. From here, most everyplace is 'higher'!
 
Thanks for the info on the newer 7448 plan on picking one up Monday. I'll get a couple sets of jets and feel it out over the next few weeks. I also will try o get some pictures up over the next day or two of the carb and differing metering blocks. Could be I'm missing something one of you guys can point out but I'm feeling I got the mix matched stuff that just wont go together properly.
 
You won't need to mess with the new carb. The metering blocks you have won't be compatible with the new carb. Use it as it is = out of the box. The only adjustment will be to check the fuel level as the factory setting using a set pressure is not going to be the same as the pressure from your fuel pump.
 
Little update, I installed the new Holley 2300 part #7448, and the truck is running. I set the timing with max vacuum using manifold and adjusted af screws with max vacuum. Runs well but still has a Rich/gassy smell. Any ideas what's causing this? Wrong plugs, coil not hot enough, pcv valve? Any thoughts I'm willing to explore. Has pertronixs, stock coil, stock dist Holley (I believe) with vacuum advance.
 
Is the choke plate all the way open? How many degrees is the timing advanced? What vacuum are you seeing at idle? Is it steady? How many turns out are the a/f screws from being seated? Are they within a quarter turn of being equal?
 
Choke plate is all the way open, vacuum is 21hg. Needle stays put no shake or bounce af screws are 1 1/4 out. 4 spd idles at 700 steady.
 
That all sounds perfect. If your static timing is anywhere between 8 and 12 degs advanced and your auto 85's are gapped to 0.40-45, you should be lighting the fires and chirping tires. IH engine exhaust does tend to be a bit funky smelling in my experience, especially when you're nosed into an open garage or carport etc with the engine running. Are you seeing heavy black smoke and soot deposits billowing out of the tail pipes like a house afire? How are your spark plug electrodes looking after you take it for a good run? A very light tan residue indicates proper a/f mix. Chalky and sooty black would mean the mix is too Rich. I don't see how that could be possible given the facts as you've presented them. This thing should be just about dialed gnats ass.
 
Hope you all don't mind me re-opening an old thread. We have a 75 1600 Loadstar with a V-345 and an Allison 545 behind it. This is an EGR motor. We intend to block off the EGR after rebuilding the carb. What jets and power valve are used in an earlier year that did not have EGR? Thanks.
 
On an EGR motor it might not be just jet changes, but passages in the carb that are different too. In general my suggestion would be to go up to sizes. The oxygenated gasoline different that what was available in '75 and it burns leaner too. And there is the elevation issue too. My guess is that you'll need a 53 or 54 jet.
 
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