Help Picking a Carb: SBF in SS or GT

[FireSale]

Originally Posted by Dwight Southerland

Welcome to the world of NHRA specs deciphering! It is a language unto itself, and you learn it by speaking it while among the tribe, much the same as learning Gaelic or Navaho.

The 1968 Ford 302-230 is available to use in the Falcon, Mustang or Cougar.

The accepted carbs for use in the Falcon or Mustang are Autolite 4300 models with Ford number C8ZF-A for the Falcon with a manual transmission ("Ford C8ZF-A/SM") and number C8ZF-B with an automatic transmission (" B/AUTO"). The Mustang uses the same Autolite model 4300 carbs with numbers C8ZF-C with a manual transmission ("Ford C8ZF-C/SM") and number C8ZF-D with an automatic transmission (" D/AUTO"). The throttle bore measurements are 1.437" primary and 1.563" secondary with a primary venturi measurement of 1.000". The carb is designed with a large butterfly at the top of the air horn on the secondaries that opens by increased air flow when the secondaries are opened, thus the is termed an "air valve". This information comes from note #10 on the tech sheet as "1437x1563/1000/AV".

The accepted carbs for use on the Cougar are Holley 4160 models with Ford number C8OF-D with a manual transmission ("Holley C8OF-D/SM") and Ford number C8ZF-B with an automatic transmission (" C8ZF-B/AUTO"). The carb is a typical Holley carb with throttle bore measurements of 1.563" for the primaries and 1.563" for the secondaries with a primary venturi measurement of 1.250" and a secondary venturi measurement of 1.313". This information comes from note #15 on the tech sheet as "1563x1563/1250x1313". This is basically a 600 cfm Holley carb.

Since NHRA allows any replacement OEM carb that has the same primary and secondary throttle bore and venturi measurements, you are not restricted to using only those carb numbers that are listed. Many Autolite carbs were manufactured during the 1967-1969 years by Ford with the same size throttle bore and venturi measurements and any are accepted. For the Holley carb, there are a gazillion different Holley carb models with those measurements, even a lot of GM and MoPar OEM carbs.

The "dash numbers" are exactly as you describe. Holley carbs are frequently identified by the Holley "list number" stamped on the choke air horn and many times the particular "list number" carb goes through a sequence of refinements that Holley identifies by adding a "dash number" to the end of the list number stamped on the air horn. Thus you have a list 3310 and a list 3310-1, 3310-2, 3310-3, etc. All the "dash number" carbs in this sequence are accepted in place of the original spec carb.

Hopefully, this will help clarify a part of the "Greek speak" of NHRA tech sheets.

Perfect.

I found a rebuilt Cougar carb from UREMCO through Summit for under $300 that will let me run as a GT car. I was afraid the /SM in the NHRA listing was "small" but it must be "Shift-Manual". There are people on eBay selling rusty cores of original carbs for the GT350 and Cougar for $600.

Now that I understand the dash number system, I'll take the specs of the 600 cfm Cougar carb and look through the list of newer Holleys.

Thanks again.

Dale