I picked up a 327 sbc recently and it came with a Rochester 4gc carb. I've never fooled with these but have been trying to think of a 2x4 intake combo that is inexpensive and not run of the mill. Anybody ever put together a dual quad using these carbs? Can anyone offer advise as to whether this is doable? Thanks.
Ive run the 4GC on an NHRA stocker with good results. Im not sure there is room for 2 of them on a factory dual quad intake that uses WCFB's. An Edelbrock for 2 AFB's would work but you would be better off using the AFB's
Don't they have pretty high cfm ratings? It would be a serious motor to be a match, provided you could work out the mechanics.
I'm just learning about these carbs, but I belive the 4gc was produced in several different sizes from under 500 cfm to over 600
Mid '50s Cadillacs and '56 Pontiacs used 4GCs on their dual quad setups, so take it from there. They will not fit on a factory '56-'61 Corvette intake, though. The fuel bowls run into each other.
I've got an Edelbrock c-26 dual quad intake. I'll have to check and see if it could accomidate a couple of 4GCs. Not sure this is the way I'll go, but thought it was someting worth at leaset contemplating.
I've been thinking this few times... 4jet carbs are often quite cheap (even cheaper than 2gc!) so buying few of those and rebuilding 'em, might give you 2x4 for much less money than using quite new Edelbrocks (or such) which you found from swapmeet.
Yep. This is exactly why I am considering this as an option. You may be able to put together a cool set up with period correct carbs for cheap.
Ok, I'm still dreamin' about this kind of set up. I've accumulated a couple of Offy cross-ram adaptors, so the problem of the fuel bowels hitting each other on my edelbrock 2x4 manifold is solved. I probably need to rebuild them, my plan is to do them one at at time and get them dialed in on my stock single 4bbl manifold, then switch to the 2X4 cross-ram set up. I'm hoping to get this done before Roundup, but we'll see.
I have a couple of Offy cross ram ADAPTERS. Each one mates a single 4bbl carb to 1/2 of a 2X4 manifold. 1 2X4 manifold, 2 adapters, plus 2 4bbl carbs = crazy cobbled together inefficient, but cool, cross ram set up.
Hey Lucky, Give Larry at Automotion a call 406-453-5395 www.hotrodcarbs.com He knows a bunch about Rochesters of all types not just 2G's Smokey
Those cross rams are way cool. 4jets are not bad, I was running one on my 55' olds before I went to 3x2. Kits can be a pain to acquire I used an NOS kit to build mine and the accelerator pump fell apart very quickly since that kit was on the shelf for so long. I used the modern plunger from a 70's q-jet and it worked great. Try bfic in burbank, ca. if you need good kits.
Do the carbs you're thinking about using have four metering rods and jets per carb ala the two found on Edelbrock/Carters? Perhaps come off a mid-late 50's ChryCo product?
Two rochester 4gc wont fit a stock corvette intake. One 4gc and one wcfb will. t The bigger 4gcs had larger secondaries OldWolf
You should have room under that big 'ol hood for that. Larry at Automation can supply the proper jets, most likely the only change needed. I take it you got the brakes/king pins done?
I'll give Larry a call and ask for advice on my set up. Thanks Uncle Lee. Yep. Got the following done (thanks to my recent breakup with my girl friend): -King Pins -Front Disk conversion -Roller bearing conversion -Drive balls out of steering arms and convert to moder style tie rod -new drag link -Install new dual circuit master -All new brake lines -Rebuild rear drum brakes -Blast and repaint diff cover -New rear shocks She should stop and steer as well as she goes now. Honestly, I cannot believe the level of Mickey Mouse B.S. If found that others had done in the past to this truck.
BTT for this thread. i'm also interested in setting up a dual 4Jet induction for an engine in the 290 to 300 c.i.d range. does anyone know the cfm rating for the 4Jet 's originally equipped on 283's? seems like they would be the most common small cfm 4Jet out there. i'm also going to assume there is some degree of interchangeability with the 2GC carbs, such as jets, etc?
Anybody running one of these C-26s with the crossram adapters? Looks cool but I wonder how it would run. Thanks Josh
Hey all, I actually ran two 4-gc's on a mild small block with a tunnel ram a while ago. It worked great for cruising at 55 or 60 but just around town it wasn't that great. Those carbs are some very finicky sons of bitches. I can't remember where I got the kits for them from but the accelerator pumps they sent me were wrong, so watch out for this. It takes time to dial them in, have patients and good luck.
ok, i just found out NAPA/Echlin #2-5043 carb kits are still available and are arguably the best currently available. Each kit retails for $26.49.
Don't forget that the Rochester 4 Jets came in two different base sizes. Buick used the small base, Chrysler, Cadillac, Chevrolet used the bigger bolt pattern. Besides the base difference, you have to think about the linkage that is in the bases you want to use.
I have a 55 caddy 2 x 4 intake on a 324 olds with the 4G . 1 and 7/16 1 or 1/8 inch primary 1and 1/4 inch secondary are rated at 465 CFM each. The early 4GC are all in this cfm range ,, later years jumped to 550 and the last ones on big inch engines are 690 cfm.