Help Picking a Carb: SBF in SS or GT
 

I'm working on a 68 Mustang coupe with a 302 and have hit the dreaded Carb Wall. The car had an Edelbrock on it when I got it, so I know I have to replace it. The Accepted Carbs list is hard to read. at least for me. The Tech out here says I have to have a factory carb in the Replaces column in order to use one of the Edelbrock or QF units listed. I also read here that you just have to match the cfm, throttle and venturi numbers. Which is correct?

The NHRA stock carb for my car is an Autolite C8ZF-D which MustangTech says is an Autolite 4300. Under the Holley tab, there is a 4150 listed as used on the 68 Mustang GT 350. NHRA lists the C8OF-D Holley for the 68 Cougar 302 for a GT build. That's Holley list 3796-1

On the topic of "dash numbers" ^^ the first page of the Product guide states that " All Holley Dash Number carbs" are accepted, so what's a dash Number? The Holley catalogue has a number of carbs, both street and race, listed as nnnn-1. Are those "dash number" carbs?

If I just need to match numbers, the NHRA is no help. Note 15 for the 68 Cougar is 1563X1563/1250X1313. Is that 1.536 (1 9/16), 1.25 and 1.3125 (1 5/16)? I think I just figured it out in this post...:o

Any help would be appreciated. I've been a fan for a long time, but this is my first build. Why Super Stock, you ask? It's where the cars are.

MustangTech Carb Page

Dale

Re: Help Picking a Carb: SBF in SS or GT
 

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.

Re: Help Picking a Carb: SBF in SS or GT
 

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

Re: Help Picking a Carb: SBF in SS or GT
 

Holley 1850 (common as dirt) is the same specs as the Cougar carb. Lots of dashes with that one, too.

If you use the Cougar spec carb, you will run SSGT, not SS.

"SM" = Synchromesh

Re: Help Picking a Carb: SBF in SS or GT
 

I think of GT as a subset of SS, but I understand the difference. When the time comes, we all answer to "Super Stock to the staging lanes".

How about this 4150?

600 cfm venturi 1.25, throttle bore 1.563?

EDIT: I passed over the 1850 because it wasn't a dash number carb. I might wind up driving to the track ($$$) so it would do me good for the first year.

Dale

Re: Help Picking a Carb: SBF in SS or GT
 

we have one of those holley carbs race ready by the famed carbsmith Brashears off of the badazz kuntz & buchannon former Kip Martin Mustang GT that at one point held every class record that the car could fit into and that was with the WRONG low compression dished pistons untill dan callahan and I CAME UP WITH the blueprints for the correct flat tops the carb had been inspected by travis and wesley both among others several times ALWAYS passed just fine it has been in my possesion since 1994 i might be persueded to part with it;)

Re: Help Picking a Carb: SBF in SS or GT
 

Alex -

I remember being told that the Autolite went down the track better (quicker) than the Holley.

Re: Help Picking a Carb: SBF in SS or GT
 

I believe that on a 289 with a 4100 Autolite dwight been there done that but not on a 302 using a 4300 Autolite, per kuntz and se I would have never bought the carb otherwise I didn't know brashears from a pair of garden shears just some mythical guy that mike edwards, kuntz,se, craft and leblanc would occasionally speak about

Re: Help Picking a Carb: SBF in SS or GT
 

It's my understanding that the 4100 is a top carb for the 289 but the 302 likes a higher cfm like 600. 4100 is 440 or something like that. The 4300 came into play at the dreaded emission era and works ok for street applications.

Alex, I'll contact you regarding that carb.

Anyone know if the Holley likes any particular manifold? Air Gap or Stealth? Don't Weiland and Holley go together like Edelbrock and Air Gap?

BTW: I read over 100 pages on this site before posting and can't tell you how much I appreciate the info.

Dale

Re: Help Picking a Carb: SBF in SS or GT
 

accepted carb.
ssr-585-vs quick fuel
holley list 1850
holley list 2818
+ the stock holley
The 1850 picked my 289 up 1 1/2 mph.the
et was almost the same, in back 2 back test. Can not run on the 289 in class races with holley have to run 108 on mustang &112 on comet