Help with my Rochester - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SJLenz1340 · 05-01-2017, 01:06 PM

I've had this truck quit some time now, a 67 C10 (327) fleetside long bed with a wood bed floor. So I chose a few projects. Replacing my Powerslide with a 200-4R which the rebuilder has now. So on to my question regarding my carb, have to add a TV cable and will likely need a geometry correction arm. Given my Rochester has no distinguishing numbers I was hopeful someone could help me identify it.
Thanks for any assistance!

demian5 · 05-01-2017, 01:18 PM

Rochester 4Jet?
Carter?

SJLenz1340 · 05-01-2017, 01:23 PM

The only markings are 4 jet, other than GM Rochester Carburetors, patent pending.

wbc409 · 05-01-2017, 05:25 PM

The key word is "should ", there should be numbers on it somewhere. A lot of the Rochester carbs have them on the back side. You might have to take it off to find them.

ray_mcavoy · 05-01-2017, 07:24 PM

That's a Rochester 4G and is the original type carburetor for your application (67 truck 327).

Back then, the model numbers were often stamped into a little brass plate that was fastened underneath one of the screws that holds the carb's air horn in place. Unfortunately, it is not uncommon for those little ID tags to have been discarded or left off if the carburetor was taken apart for service or rebuild.

**Steeveedee** · 05-01-2017, 08:45 PM

Depending on where you are at with money, you could replace the intake, air cleaner housing and carb with a Quadrajet unit. They are very common, so shouldn't cost too much. But if this runs OK, you can look at a late model car with a Q-Jet and 200-4R and copy the length of the lever. I did that with an Edelbrock on my Buick when I had a SBC and 700 (4R) in it.

Alex V. · 05-01-2017, 09:16 PM

That's a Rochester 4G, 4GC, 4 Jet - as others have said, correct for your '67 220HP 327 and usually only had a tag under one of the top screws for identification of exact model/specs. A good carburetor IMHO. Not as refined as the Quadrajet, but not a piece of garbage, either, and easier to tune than a Q-jet.

**Steeveedee** · 05-01-2017, 11:23 PM

Quote:

Originally Posted by Alex V.

That's a Rochester 4G, 4GC, 4 Jet - as others have said, correct for your '67 220HP 327 and usually only had a tag under one of the top screws for identification of exact model/specs. A good carburetor IMHO. Not as refined as the Quadrajet, but not a piece of garbage, either, and easier to tune than a Q-jet.

Agree 100%, but it's missing all the choke hardware (except the flap at the air horn). I put one of these on my '64 Malibu SS back in '70 (swapped from 2 bbl to 4 bbl), and it worked well. Of course, the Q-Jet he gets might be may be missing all the choke hardware, too.

SJLenz1340 · 05-02-2017, 09:02 AM

Thanks for the help! I'm aware of the number tag and of course mine is missing. Checked the back side of the carb but still no identifying marks. Picking up my trans on Friday and need to make all the ancillary part arrangements.
This guy uses a manual choke from the dash. Probably a bunch of stuff missing, but in 50 years things get lost. Presently it works ok, but I think it could use a rebuild. It is possible I may perform some sort of carb rebuild/replace/retrofit, but not immediately.
Again thanks for the help.

68is4me · 05-02-2017, 09:04 AM

Quote:

Originally Posted by Steeveedee

Agree 100%, but it's missing all the choke hardware (except the flap at the air horn). I put one of these on my '64 Malibu SS back in '70 (swapped from 2 bbl to 4 bbl), and it worked well. Of course, the Q-Jet he gets might be may be missing all the choke hardware, too.

I don't know anything about these carbs, but looks like it has a manual choke setup on it. I think that manual choke was factory.

demian5 · 05-02-2017, 11:34 AM

I have the original 4 Jet in my 64 impala. I rebuilt it years ago. Runs great, has the heat pipe through the exhaust manifold for the choke.

I did learn the hard way that you must adjust the the float 1/8" lower than spec so it doesn't flood out at lights on hot days. Originally has some kind of spring on the float to help close the needle, but that isn't in the kit!

LongBox · 05-02-2017, 02:30 PM

The 4 G Rochester is just two 2G Rochesters in a single casting. Easy to work on, just like tuning 2 2Gs.

**Steeveedee** · 05-02-2017, 04:04 PM

Quote:

Originally Posted by 68is4me

I don't know anything about these carbs, but looks like it has a manual choke setup on it. I think that manual choke was factory.

Yeah, I missed that manual choke cable on my first look. heh heh

Alex V. · 05-02-2017, 10:26 PM

Quote:

Originally Posted by LongBox

The 4 G Rochester is just two 2G Rochesters in a single casting. Easy to work on, just like tuning 2 2Gs.

What about the auxilary throttle valve in the secondaries?

05-01-2017, 01:06 PM	#1
SJLenz1340 Registered User Join Date: Jun 2014 Location: Ingleside, IL Posts: 56	Help with my Rochester I've had this truck quit some time now, a 67 C10 (327) fleetside long bed with a wood bed floor. So I chose a few projects. Replacing my Powerslide with a 200-4R which the rebuilder has now. So on to my question regarding my carb, have to add a TV cable and will likely need a geometry correction arm. Given my Rochester has no distinguishing numbers I was hopeful someone could help me identify it. Thanks for any assistance! Attached Images

05-01-2017, 01:18 PM	#2
demian5 Registered User Join Date: Aug 2016 Location: Lake Forest, CA Posts: 2,177	Re: Help with my Rochester Rochester 4Jet? Carter? __________________ "Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC

05-01-2017, 01:23 PM	#3
SJLenz1340 Registered User Join Date: Jun 2014 Location: Ingleside, IL Posts: 56	Re: Help with my Rochester The only markings are 4 jet, other than GM Rochester Carburetors, patent pending.

05-01-2017, 05:25 PM	#4
wbc409 Registered User Join Date: Mar 2015 Location: st cloud mn Posts: 163	Re: Help with my Rochester The key word is "should ", there should be numbers on it somewhere. A lot of the Rochester carbs have them on the back side. You might have to take it off to find them.

05-01-2017, 07:24 PM	#5
ray_mcavoy Registered User Join Date: Nov 2009 Location: Sherman, ME Posts: 2,366	Re: Help with my Rochester That's a Rochester 4G and is the original type carburetor for your application (67 truck 327). Back then, the model numbers were often stamped into a little brass plate that was fastened underneath one of the screws that holds the carb's air horn in place. Unfortunately, it is not uncommon for those little ID tags to have been discarded or left off if the carburetor was taken apart for service or rebuild.

05-01-2017, 08:45 PM	#6
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,724	Re: Help with my Rochester Depending on where you are at with money, you could replace the intake, air cleaner housing and carb with a Quadrajet unit. They are very common, so shouldn't cost too much. But if this runs OK, you can look at a late model car with a Q-Jet and 200-4R and copy the length of the lever. I did that with an Edelbrock on my Buick when I had a SBC and 700 (4R) in it. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

05-01-2017, 09:16 PM	#7
Alex V. Registered User Join Date: Mar 2013 Location: Campbellsville, KY Posts: 888	Re: Help with my Rochester That's a Rochester 4G, 4GC, 4 Jet - as others have said, correct for your '67 220HP 327 and usually only had a tag under one of the top screws for identification of exact model/specs. A good carburetor IMHO. Not as refined as the Quadrajet, but not a piece of garbage, either, and easier to tune than a Q-jet. __________________ Alex V. ------ 1967 C10 Suburban, 350/NP435, Green/Green, PS, PB, HD cooling, charging, shocks, and springs. 1985 GMC C3500 SRW, Sierra Classic, 454/TH400, white/blue.

05-02-2017, 09:02 AM	#9
SJLenz1340 Registered User Join Date: Jun 2014 Location: Ingleside, IL Posts: 56	Re: Help with my Rochester Thanks for the help! I'm aware of the number tag and of course mine is missing. Checked the back side of the carb but still no identifying marks. Picking up my trans on Friday and need to make all the ancillary part arrangements. This guy uses a manual choke from the dash. Probably a bunch of stuff missing, but in 50 years things get lost. Presently it works ok, but I think it could use a rebuild. It is possible I may perform some sort of carb rebuild/replace/retrofit, but not immediately. Again thanks for the help.

05-02-2017, 11:34 AM	#11
demian5 Registered User Join Date: Aug 2016 Location: Lake Forest, CA Posts: 2,177	Re: Help with my Rochester I have the original 4 Jet in my 64 impala. I rebuilt it years ago. Runs great, has the heat pipe through the exhaust manifold for the choke. I did learn the hard way that you must adjust the the float 1/8" lower than spec so it doesn't flood out at lights on hot days. Originally has some kind of spring on the float to help close the needle, but that isn't in the kit! __________________ "Work hard, use your vacation days." 1970 C15 GMC Long Bed 1986 C20 Scottsdale 1983 K2500 Sierra Classic Suburban 6.2 Instagram: C10sofOC

05-02-2017, 02:30 PM	#12
LongBox Registered User Join Date: Sep 2016 Location: Vancouver BC Posts: 784	Re: Help with my Rochester The 4 G Rochester is just two 2G Rochesters in a single casting. Easy to work on, just like tuning 2 2Gs. __________________ Rick -69 GMC 910 Long Box, 350 -98 Chev Silverado 1500, 350 Vortec 4L60e -08 Mustang GT Convertible



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