1968 Cougar 390 4 speed Carburetor Suggestion

I’m restoring a 68 Cougar 390 with a 4 speed. The original Holley is missing. What is best, the original Holley 600 or upgrade to a modern Holley? A local speed shop suggested Holley Street Avenger 750. The 390 is stock and numbers matching.
Ric in Simi Valley

600 cfm was what the factory used.



Quality on the new Chinese made Holley Street Avenger series carburetors is lackluster. The problem that I have had is the zinc plating flaking off inside the float bowls which clogs the carburetor.

A better choice is the dichromate finished 600 CFM carburetor like this:

Of course the best possible choice is the original carburetor. Several people restore them. Cost is a bit more, but you won’t likely ever need another one.

I have a 66 and 67 390 GT Holley carbs. They need rebuilt. If either one will work, shoot me a PM and I can send pics. - Matt

Two things to consider: One, the original was center-pivot floats, and it’ll feel great to see those when you remove the air cleaner; two, an original one rebuilt will solve the problem of “universal” Holleys having the fuel inlet stuff on the wrong (non-Ford) side. Seeing that screw-in filter on the driver’s side (i.e., not that twin-feed like the old 3310) will also feel great!

Send me to the re-education camp if I’m wrong. But didn’t 67 and 68 390 S codes come with 4150 715 CFM Holleys? And 69 390 (IP) S code come with the 4300 600 CFM?

390 Holley carbs were 600 CFM. 715 CFM was the 65-67 Shelby “Lemans” bowl carburetors.
I would put a 735CFM " Cobra Jet" Holley on it if it was my car. I think you can find a -“U” replacement carb reasonably priced, especially with a 70’s date code.

I agree with the recommendation to use an original Ford Holley. Not that an aftermarket unit can’t be made to function just fine, but as others have pointed out, they just don’t have the right look. The original 600 cfm units are pretty widely available and it shouldn’t be difficult to find a reasonably priced example. They work well, and if the car is otherwise all stock, that’s what I’d go with. As Mike mentioned, the 735 CJ Holley is externally almost identical, and is a good choice for a stealthly performance boost. The old Ford “Muscle Parts” handbook recommended this very change. Getting full benefit, however, requires additional modifications, such as headers or CJ exhaust manifolds, and the CJ or an aluminum high-flow intake. Unless you find a super bargain on a CJ carb, the gains to be had on an otherwise stock 390 don’t justify the additional expense, in my mind.
In either case, restoring a neglected Holley to fully functional status isn’t particularly difficult, it just requires some time and attention to detail. Always use genuine Holley parts, and remember that cleanliness is critical.
The chemicals and supplies necessary for appearance restoration are more of an investment than is practical for the typical hobbyist. If that’s important, someone like Drew at Air Fuel Spark can restore both the function and appearance to like new.
Sounds like a really neat car. Good luck!

I have a correct '68 390 GT 4 Speed (C80F-9510-AA) professionally restored carburetor with a date code of 832 (2nd week of March, 1968) available. Send me a note if you are interested.

If I’m not mistaken that is a 68 1/2 Cobra Jet 4 speed carburetor. Extremely rare and valuable:https://www.ebay.com/itm/1968-4174-HOLLEY-DATED-852-SHELBY-GT500-KR-C8OF-9510-AA-MUSTANG-SUPER-YEAR-WARR-/264180229999?epid=1129944188&hash=item3d825e676f%3Ag%3AAYkAAOSw8gVX9832&nma=true&si=52PW79hXMX9JKSnZHsWI0HeXstM%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

The 68 390 GT 4 speed carb is C8OF-9510-C.

Steve, you could very well be right. I had a '68 Fairlane Cobra Jet a while back and may have sent the carb off it to be restored and confused it with the carb I had restored for my Cougar GT. This link seems to confirm what you said. I will do more homework. If true, I am very grateful for the quick reply and help. Thanks so much, Evan


I found a Holley C9AF-9510-U Carb on Ebay. Ford replacement 1970 for 428/390. It has 735 CFM vs 600 cfm stock. The cost was reasonable, 400.
Thanks for the suggestion Mike.
Ric out
1968 Cougar 390 4 speed

Ok I did find a 735CFM " Cobra Jet" Holley “U” replacement carb. Works fantastic on stock 390 S code with the four speed. Thanks for all the input.
68 Cougar S Code 4 speed

Holley 3310