I just bought 2 NOS Holley 1945 economasters for a good price.
Looks exactly the same, but part numbers are different:
1. HOLLEY part #2-304 (list 8994-AAA)
2. HOLLEY part #2-278 (list 7611-1AAA)
I'm wondering what the Holley book says about them. What the difference could be?

Thanks.

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"Hey, I like that paint job you got. What they call that--sorta a cross between Piss Yellow and Puke Green, ain't it?" -- Bob Falfa

(list 7611-1AAA] 1975-76 chrysler 225 engine auto trans Fed emissions jet 623 8994-AAA 1975-77 chrysler 225 eng All trans After market replacement. jet 622

Inquiring minds want to know... Which jet is richer and by how much? How much difference tuning the two carbs would there be?
Or would it be advisable to jet the two carbs the same, or re-jet both for best performance in the dual setup?

BC

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'64 Dart GT convertible, 64 Dart 170 2-door post sedan in faded blue and rust (the Az Dart) & a sixty THREE Dart 170 2-door post sedan in faded blue and rust. (future project)
Early Dart Disorder (EDD) is real, and I've got it!

Thanks
Aha! interesting thinking, I see where you're going

I don't have a dual setup in mind myself since I'm on a low budget, partial rebuilt to get decent mpg out of that heavy box my van is.
Previous carb was a wrong year, wrong application, missing parts piece of junk, so I bought the 1st economaster as a replacement. The 2nd came up pretty cheap on ebay and I just couldn't pass up the deal.

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"Hey, I like that paint job you got. What they call that--sorta a cross between Piss Yellow and Puke Green, ain't it?" -- Bob Falfa

You wouldn't notice in typical 'tuning' mode the difference in the 3 digit jet as Holley produced these to have tighter specifications than the standard jets you would normally find in their catalog. They have a 60% tighter control on the jetting than the standard jet (per Holley's technical statements).
The suffix determines if they are leaner ='1', in the middle ='2', or a little richer '3' of the jet range. So the 623 jet will be a little richer than a 622 jet, and both will be tighter in jetting than the normal #62 jet.

Like I stated these were for carbs that had emissions calibration and so if you put a pair of #623's into a Holley 2300 500cfm, you would not notice any difference over a pair of #62 standard jets, but if running in a small 1-barrel and taking a tailpipe sniff test at the local smog shop you might notice a subtle difference.

FYI.

-D.Idiot