Holley Carb Identification Experts

[ykf7b0]

I have Holley mechanical secondary double pump carb that has the choke horn milled off. The numbers I do have are P 46 on the driver side of the main body and R 24 on the passenger side of the main body. Also I have 172 on the primary throttle blades and 173 on the secondary blades. I only have a power valve on the primary side. The original owner sold it as a 850 but I'm not so sure. I would like to hear from the Holley experts and get a better idea of what I have.

 

[Cranky]

Is it a double pumper and what are the throttle plate bore diameters?

 

[ykf7b0]

Yes double pumper. 1 9/16" throttle blades all around.

 

[Cranky]

If it were and 850 DP, the venturii would be 1 9/16" both primary and secondary and 1 3/4 throttle plates on both front and rear....

http://documents.holley.com/techlibrary_carb_numerical_listing.pdf

 

[ykf7b0]

Thanks Cranky. Definitely not an 850 but what else can I do to verify whether it is a 780 or 750 possibly? Boosters are drop down.

 

[ckessel]

Sometimes the Holley LIST number is stamped on a metering block. Look for a four and possibly five digit number like 4782 or L4782. Any id number you need will be stamped not cast. Otherwise like Cranky said, its measurement time.

 

[ykf7b0]

I haven't found anything other than 8543 on one metering block and 6501 on the other. We have established it's not an 850 and the information I have found so far looks like alot of parts interchanged between 600 and 750 cfm so it very well might be anyone's guess.

 

[65-440]

600's are stamped 109, 650-750 butterflies are 172's .... but I have a double pumper 750 AED stamped 180 .... good luck !

 

[PurpleBeeper]

The only thing that strikes me is the different numbers on the two metering blocks... shouldn't they be the same? Or, doesn't it matter since the back metering block apparently has a plug in the power valve hole. And don't double-pumpers have power valves front & back? It sort of sounds like maybe a hodge-podge of Holley parts put together.

 

[lewtot184]

a 600 would have 1 9/16" throttle bores.

 

[ckessel]

Your purchase might make a good parts unit since it sounds like there are some issues. You could always toss a kit at it and see if it works and go from there.

 

[ykf7b0]

What issues? Got it on and tuned in today. Runs like a scalded dog on my built 440. I'm am just curious as to what I have is all. My neighbor had ran it on his sbc Camaro drag car and he removed it to install a carb already set up to run alcohol.

 

[ckessel]

You are good to go!

 

[ykf7b0]

A racer friend with Holley experience came over and took a look and he believes it is an 800 cfm. ???

 

[ykf7b0]

Carb in question has 1 3/8 venturies front and rear along with 1 11/16 throttle bore diameters front and rear. It's 750 cfm.