How to ID a Holley 350 or 500

[Anonymous]

Well??????
I bought a 500cfm Holley (so I was told) $25
I decided the 350 Holley might be better for a daily driver.
so I bought what I was told could be a 350 ($20). The guy didn't know, but said it came off a pinto motor that was in his sand rail.

I looked at both of them and they look and measure the same.

In David's Falcon book it say the 350 has 1.187" venturi and 1.375 throttle bores
It also states the 500 has 1.375 venturi and 1.69 throttle bores.

The 2 I have, the throttle bores are 1.5" I'm not sure where to measure the venturi

what are they? where is the number to ID these things?

 

[80Stang]

You'll find the model number stamped to the choke horn, like 'LIST=xxxx'. The four numbers tell you what carb it is. Most common 350cfm is 7448 and the 500 is 4412.

 

[Anonymous]

Both say LIST 7508-1

the thought to be 350 says;
LIST 7508-1
3558

the thought to be 500 says;
LIST 7508-1
0414

 

[mustang6]

Does it look like this one on ebay?

http://cgi.ebay.ca/7508-350-CFM-HOL...046337652QQihZ002QQcategoryZ317QQcmdZViewItem

 

[Anonymous]

That's what they look like.
But it's to my understanding that they look the same.

 

[mustang6]

That is not what the fuel bowl on a "normal" 350 or 500 cfm looks like, so the 7508-1 is a bit of a different animal. The ebay ad says it is a 350 cfm, but I also found this information on a Mercury Cougar forum:

I've gone to the Holley website and could not find anything to cross referece this number with. I think I want to rebuild this one for fun. I'm a really boring guy...

Here's what is stamped on the carb
LIST 7508-1
and below that 0810

I printed out this document that was supposed to have every model number they ever made from the Holley website. 7508 or 0810 aren't on there.

http://www.mercurycougar.net/forums/attachment.php?attachmentid=2397&d=1054010535

Good thing you included a picture. I looked in the buyers guide listings in the 1992 Holley Performance Parts Catalog and #7508 isn't there. The catalog skips from 7456 to 7556.

So I started cruising through the pictures to see if I saw one like yours with that rather distinctive fuel bowl. Paydirt on page 37 at the bottom. That, my friend, is a 280cfm two-barrel replacement for the dreaded Variable Venturi carburetor.

Interestingly the carb is not mentioned anywhere else in the catalog that I can find. Further, the part number shows as 1-591 for the non-feedback carb (which is the one I think you have since I can't see the feedback motor from a V. V. carb stuck on it anywhere), and 1-684 for the feedback version. This is interesting in itself as Holley part numbers that I'm familiar with start with 0- and the have a four or five digit suffix. Perhaps since it is not a performance carb it is listed under some replacement part category.

If it's an economy replacement carb then watch out as it will have the backwards" idle mixture adjustments - screw in to richen, & back out to lean.

 

[xctasy]

Your right on.


The info on the 500 is that the throttles are 1.6875"


If its throttles are 1.5", its 350, 320 or 280.


That is unlike some of the other side float Holleys I've seen, it doesn't have the funny vacum line above it.

There are a lot of old side bowl hinged 350 cfm items with bowl vent and purge lever for emissions. I've seen three found on ebay,about 1974 to 1975, very common. There was a large redesign with a wierd Economizer venturi, still called a 350, but other evidence says its 320 cfm.

There are about 6 common list 350 and 500's.

The 'emissions area' carbs were factory orders. By that, I mean a carb that has US 1972 compliant vapour recovery lines and reverse idle. It is written that the 350 and 500 are not emissions area carbs. Yes, after about 1976, most had reverse idle mixtures, but there are a lot of these vented special clearance items for overseas carb sales. They are not listed by Holley.

Even quite late in to the 1980's, items like 9117 350 cfm carbs with the ancient side hinged bowl, reverse idle and bowl vent and purge lever. I've found two here in NZ, and they were common aftermarket carbs packaged for Lynx. Similar to ones I've seen on SP 221 Fords.

 

[Anonymous]

Here are a few pictures. The calipers read 1.47"
if the site moderator would like me to delete these after we figure out what they are, I will. I don't want to take up to much space on the site.
The carb with the little red triangle, I was told is the 500.
They look the same except for the choke.

let me know if you need another angle

 

[Anonymous]

I took them over to a carb shop to get an answer.
The 7508 is a replacement for a stock Motorcraft, used from 62-74.
They went on just about all V-8's, and had a few different sizes.
The ones I bought were not 500's. He show'ed me one, and it had pretty big venturi and throttle bores. He thought them to not even be 350's but maybe more like 300cfm. Said he couldn't tell until he got them apart and did some measuring, because both had been worked on at sometime in the past.

So, there ya have it.
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