Author Topic: Holley carb engineering numbers  (Read 1242 times)

Offline preaction

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Holley carb engineering numbers
« on: November 16, 2018, 06:42:02 PM »
When Holley carbs were manufactured how were the engineering numbers applied was a roll stamp used it seems a hand stamp would not fit a production line as some hard to find carbs become more expensive and getting more scrutiny the more it seems to me that some engineering numbers have the look of a hand stamping and I have recently seen the same model carb with some letters of a different font can this be typical ?
8F02R218047-  July 18 1968   Dearborn

Offline J_Speegle

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Re: Holley carb engineering numbers
« Reply #1 on: November 17, 2018, 02:13:31 AM »
Pulled up a dozen or so that were handy and given what appears to be a very uniform depth, spread and look I would guess that they were machined stamped. Now each line may have been stamped or pressed individually or all three at the same time but the depth from line to line, looking at the examples I have they are very uniform. Different looking could always suggest the possibility IMHO of attempts to alter the original stampings for a more favorable/valuable one 

As far as different font. What time period are we looking at and what model/application? Just so we can compare apple to apples
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline preaction

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Re: Holley carb engineering numbers
« Reply #2 on: November 17, 2018, 04:16:58 PM »
Thanks for the look up Jeff the  time period would be June 68 for a C8OE-AA.
8F02R218047-  July 18 1968   Dearborn

Offline J_Speegle

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Re: Holley carb engineering numbers
« Reply #3 on: November 18, 2018, 02:00:24 AM »
Thanks for the look up Jeff the  time period would be June 68 for a C8OE-AA.

Thanks a bunch for the additional info. Carbs from that period appear to be stamped differently from the initial ones I randomly pulled up and reported on in Reply #2.

Stamping on ones from this period are not as consistent, are not lined up or spaced as equally as the others so it was a good idea we focused on specific

Will post a couple of pictures of similar carbs (think I have more -AB's than I do -AA's  and we'll continue the discussion ;)
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline preaction

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Re: Holley carb engineering numbers
« Reply #4 on: November 18, 2018, 02:29:06 PM »
It was the "O" in the third character that caught my attention.
8F02R218047-  July 18 1968   Dearborn

Offline RoyceP

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Re: Holley carb engineering numbers
« Reply #5 on: November 19, 2018, 11:08:28 AM »
Here's mine. The font looks really similar - if not identical -  to me.
1968 W code 427 Cougar XR-7 GTE Feb 23 Dearborn C6 / 3.50 open
1968 R code 428CJ Cougar XR-7 May 13 Dearborn C6 / 3.91 T - Lock

Offline Bob Gaines

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Re: Holley carb engineering numbers
« Reply #6 on: November 19, 2018, 04:04:44 PM »
It appears that all of the stamps had the letters and numbers individually stamped by all of the variations up and down. All look to be about the same depth and font just not in a straight line.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline J_Speegle

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Re: Holley carb engineering numbers
« Reply #7 on: November 19, 2018, 05:07:15 PM »
It was the "O" in the third character that caught my attention.

We have a number of things going on in the pictures you provided.

First the alignment and second the choice of fonts/stamps

Since all of the letters and numbers are well aligned as far as individually vertically and horizontally I believe they were not individually stamped but the holder allow for alignment between the individual letters to not line up horizontally in a gang stamp/holder.  The apparent equal depths across the letters and numbers from top to bottom and left to right IMHO suggests that a machine was used to press them into the metal rather than being stamped by striking them by hand

As far as your top picture and the odd first O in your top picture is unusual and looking through the pictures I have I could not find another example with the round style for the "O". Is the the date on that carb later - service replacement possibly?

Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline preaction

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Re: Holley carb engineering numbers
« Reply #8 on: November 19, 2018, 08:56:33 PM »
Jeff, Bob and Royce thanks for the replys both pics are of carbs dated before the end of 68.5  production.
8F02R218047-  July 18 1968   Dearborn

Offline 67_1183

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Re: Holley carb engineering numbers
« Reply #9 on: November 19, 2018, 09:36:52 PM »
As far as your top picture and the odd first O in your top picture is unusual and looking through the pictures I have I could not find another example with the round style for the "O". Is the the date on that carb later - service replacement possibly?

I think it is from a carb being offered for sale.  Here is the pic with the date code.

Link:

https://www.ebay.com/itm/372503350429
« Last Edit: November 19, 2018, 09:39:08 PM by 67_1183 »
2nd owner of 1967 GT-500 #1183 since September 1976