I have an Edelbrock c-26 manifold with Carter comp.series 500cfm carbs that I picked up at swap meet at least 25 years ago. Plan was to use it on Sbc 4speed 35 Ford pickup. Since that project is on back burner ,have decided to run it on 383 Sbc in 59 gmc I hope to have back on road next summer. I do realize that it will make more power with single Holley 770 on it presently. I like the look of 2x4 setups and would like to get it in use and working while I’m still able to drive. Neither carb has any provision for a choke. The holes in carb top and air horn are not drilled. Have looked on line for used carbs matching these with choke. These are the 4000 series carbs and in 500cfm haven’t found any. I don’t plan much cold weather running so am I worrying about a non issue. Opinions welcome.I have also wondered if Carter sold carbs as pairs for 2x4 setups. Carb numbers are K1 4761s and L2 4761s. I apologize for no pictures. Have to get my sons help with that.I appreciate any input. Have read that I will need to run phenolic spacers to keep fuel from boiling. Thanks
The matching 500 CFM to the 4761s is the 4758s. If you are just wishing chokes, I am pretty sure the tops from the 4759s (625 CFM) will interchange perfectly. The 4759s are MUCH more common. Carter did advertise the 4758s / 4761s (both 500 CFM) as a set; likewise the 4760s / 4762s (750 CFM). But they were also offered individually. For some reason, Carter did not offer the 625 CFM in a chokeless mode. Yet the 625's outsold the 500's and 750's combined. Carter sold AFB's in sizes from 381 to 939 CFM. I have no hard published sales numbers, but from experience, I would GUESS that, out of every 100 of the Comp series sold, the breakdown would be approximately 10 500's, 70 625's, and 20 750's. The 500's were a "hard sell" (and still are). You know, bigger is better ! The 625's might be even higher ! These are some of my absolute favorite carburetors; I have two of the 625's on a 390 and use straight linkage. And yes, I have chokes on both, as this is a street vehicle (they run better WITH chokes below maybe 5000 RPM). The chokes IMPROVE low velocity (read as lower RPM) air flow. And more trivial information: your K1 is November or December 1971 or 1981, and the L2 is either November or December 1972 or 1982. The either / or on the month depends on whether Carter used the letter "I" in their dating in the given year. Sometimes they did, sometimes they did not 4758s and 4759s were both released 4 December 1968. 4760s and 4761s were both released 5 December 1968. 4762s was released 6 December 1968. I do not have a cancellation date, but all 5 models received modifications in 1982. Calibration will not be perfect for your 383 SBC, but should be in the ball park. My Ford didn't like the stock (Chevrolet) calibration AT ALL !!! A major calibration change was required. Jon
Welcome to the HAMB from Illinois. Jon, above, is our carb expert, study his info/advice post thoroughly.
Thanks Jon, you have answered all my questions. I ‘ll bet they were manufactured in 81 as the carbs and manifold didn’t show much use when I got them. They have received most of their dirt while sitting on my shelves. Will look into 625 top. Thanks again,much appreciated Roger
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