Difference in 715 Holley Stampings

[Shelby_r_b]

I have two service replacement carbs that are stamped differently, and I'm curious as to why the differences.

Attached are two pictures. As you can see, the first picture has three rows of stampings and the second picture has two rows.

Can anyone shed some light?
Thanks!

[Bob Gaines]

I have two service replacement carbs that are stamped differently, and I'm curious as to why the differences.

Attached are two pictures. As you can see, the first picture has three rows of stampings and the second picture has two rows.

Can anyone shed some light?
Thanks!

Both are replacements mfg much later the then production. The Julen date code gives them away.

[Shelby_r_b]

Understood. But, is there a reason they went to 3 row versus 2 row stampings? Does this signify anything?

[Royce Peterson]

The three row carburetor is earlier. The two row carburetor only has the Holley list number. If they had been ordered for a customer then the three row version would have the customer's part number.

Asterisk - There might have been main bodies or even complete carburetors made with the customer part number by mistake. So the presence of the customer part number does not necessarily mean a customer ordered it - but it is likely.

You sometimes see the same thing on earlier 0-3310 carburetors even when they are new in a 1960's Holley (not generic motors) box.

Understood. But, is there a reason they went to 3 row versus 2 row stampings? Does this signify anything?

[Shelby_r_b]

The three row carburetor is earlier. The two row carburetor only has the Holley list number. If they had been ordered for a customer then the three row version would have the customer's part number.

Asterisk - There might have been main bodies or even complete carburetors made with the customer part number by mistake. So the presence of the customer part number does not necessarily mean a customer ordered it - but it is likely.

You sometimes see the same thing on earlier 0-3310 carburetors even when they are new in a 1960's Holley (not generic motors) box.

Understood. But, is there a reason they went to 3 row versus 2 row stampings? Does this signify anything?

Awesome - thanks!

[Bob Gaines]

Understood. But, is there a reason they went to 3 row versus 2 row stampings? Does this signify anything?

No real difference . probably signify's a mistake. Given the date codes and other small differences compared to vintage one isn't anymore desirable then the other. Just by happenstance in this case most likely but FYI S2MS marked carb was always used on the 66 and 67 cars. The ones with just the list number 3259 and no S2MS were used on 65 . In the case of these carbs they both have 66 List numbers but one is missing the S2MS stamping.

[gt350hr]

   Not a mistake. Ford sold these carburetors through Ford Motorsports and they did not have the S2MS 9510-A on them. In fact none of the ones Ford Motorsports sold had the original part number on them. Late 80's catalogs show the offerings.
    Randy