So I picked up a old Edelbrock manifold and carb at the swapmeet for dirt cheap. I have been looking for a old manifold with oil filler tube. I can not find any marking to identify this carb other then Rochester 4 jet and 3663 in the intake any ideas?
It looks like an early-mid 60s Chevy 4GC. It's also missing the choke shaft and butterfly and associated linkage. The tag that was under one of the screws holding the air horn on, was how you identified the carb. But the tag, like most, is long gone. That makes it challenging.
well, gets me closer to finding out, at least its just choke stuff missing, i live in Arizona dont need no stinking choke
The Rochester 4GC models came out in at least the early 60's...used on 327's and others..very easy to rebuild and available kits are pretty universal for many years....here is some more info. for you: Rochester 4GC Carburetors Information and General Operation - autohistorypreservationsociety.org
Never understand why people do that. Unless it's an all-out racing engine, just wire the choke open and leave all the other bits intact. Plus it's easier to do it that way. They probably discarded the I.D. tag at the same time. Bastages . . !
Well that's a little disappointing, I got the low 2nd one... I don't think that sill run well on my sbc400.
First used in Olds and Cadillac in 1952. Somehow, I managed to accumulate THREE matching (yep, with the the brass tags) of these from 1953 stick shift Oldsmobiles. I'm gonna use them on the Old Offenhauser dual quad manifold on my '51 Rocket.
Do the throttle bores measure 1 7/16, or 1 9/16; hard to tell from a picture, but looks like the larger measurement. Jon
Removing the choke butterfly for a street driven car is virtually ALWAYS a bad idea, even if you do live in Arizona. The choke butterfly acts as a "straightening vane" to minimize incoming air eddy currents; and actually improves low to mid-range airflow, as well as efficiency, as the air velocity is increased. For years, we built Rochester 2-G carbs for the dirt-track racers. We would narrow the choke shaft, but left it in position. We also used the power valve the way the engineers designed it to work. The Rochester 4-GC is a great carb, if you don't need more than 700 CFM. In the hands of someone who understands them, they can be modified to run as well as anything else up to their CFM limit. And they make an excellent "stealth" carburetor. "Is it stock? Of course its stock, shucks, I am still running the ole 4-jet" Engineers really do understand what they are designing. Jon
They are a little longer than their small base Carter WCFB counter parts. I hope the Offy for the Olds have the bases spread far enough to fit. From what I read in 53 if the Carter was being replaced under warranty on the Buick, Olds, Cadillac a Rochester was installed.
It's definitely Chevrolet. They moved the choke housing from the air horn down to the main body in '59, and I think that they went from two bowl vents to four later than that. It could be from either a 283 or a 250 hp 327.
There's those damned "eddy currents" popping up again! Despicable little creatures, they are. I hate 'em! Or at least I'm beginning to.
Money! GM owned Rochester, so the replacement carbs cost them less than buying from Carter. Why did they not use all Rochesters as original? GM was paranoid about strikes, and wanted two vendors. Olds, Buick and Cadillac had two vendors in the 1930's and 1940's Chevrolet and Pontiac used Carter until the 1950's. Jon
You mentioned it was too small for a 400 Chevrolet. When the 400 came out in 1970, it had a two barrel as stock equipment, my Dad bought one brand new in 1970 in a Monte Carlo. Unless this 400 is an all out race engine, a 4GC will be plenty.
With the missing choke parts and drilled throttle blades I would not put any effort into it for a street application.
OOoooo! Good eye, there! I missed that detail. Even looks like the secondaries were drilled too. Though I'm not quite sure why . . .
That carb fit the 300 hp 327 intake I used to have that ended up on several engines I had over the years. This isn't the intake I had but a 64 327 300 hp intake listed on Ebay that that carb was originally designed to go on. That is as close as I can come to and ID on the carb. Up date here, I should have remembered but in the 62 327 thread some info came up and I came up with some. On a 250 Hp 327 with that style of carb (300 hp had an AFB) the primaries were 1.4375 and the secondaries were 1.4375. the AFB on the 300 hp had 1.5625 Primaries and 1.6875 secondaries.
i didnt notice that until now, well... lucky i know a carb guy who has over 500 carb cores laying around he might have one
Don't know for sure but this GM carb looks later 60's or 1970's. Usually there was a metal small ID tag that was attached to a top screw on the top half of the carb. (If it was 60's) That tag was the carb piece number. There weren't actual ID numbers stamped om carb body, as you can see. Later the carb number was stamped on side of carb. Did a quick google search... I didn't spend any time looking through this, buy might. https://www.chevyhardcore.com/tech-stories/choose-your-quadrajet-number-identification-guide/ Had lots of them back in the day.
Some of the 4-GC carbs DID have PART of the identification number stamped: https://www.thecarburetorshop.com/Carburetor_ID_Rochester_4G.htm The one pictured in this thread does not. Jon
Yes, I've seen 4GCs from the 1954-58 vintage with the last four digits of the I.D. number stamped in the top, towards the rear.
Throttle bore diameter and the actual throttle arm are probably the only way to ID it. As for getting a kit, most parts houses for that series are a bit generic with two or three gaskets for certain positons such as air horn to body and body to throttle plate in the kit while Carb King would send you a kit that was for the carb on the tag if it had a tag. That mainly means that when you take the carb apart you carefully remove the gaskets and set them to the side so you can match them with the new gaskets to get the correct ones. No sample gasket to go by and it becomes a guessing game of matching puzzle pieces.
Looks like 66 283 PP carb to me, judging by the primary tin horn boosters. 65 327 /250 had the same size though. The small one on your list. I suppose you could tig weld up the holes in the primary side. It would probably move the car along okay with the 400. Really, you should look for a Q-jet. You'll need and adapter for that manifold though.
Ran them for years in the 70's , Super Stock combos. The TM 1 , then the Torker manifolds were the best, out of the box. (Open style adapters) Later manifolds had the straight bolt on pattern.
That intake looks like a Torker (maybe it’s a tarantula?)I never ran one on a SBC, but did with my 454. Didn’t seem to do anything until 3k RPMs or so. Edit: I zoomed in on it, it’s a TM1. Disregard the above, no experience with it.
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