Roch Carb Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skillet · 03-10-2010, 06:12 PM

As far as Rochester quadrajet carbs go, is it better(as in run better) to get the exact carb for your year(mine would be '69 auto 350) or just use something that works. I currently use a 17058213(which is for '73-'78), which seems to work good.

Wrenchbender Ret · 03-10-2010, 06:29 PM

The choke systems varied by the years. Sometimes you have to use a carb to match the intake manifold. Other then that it is the displacement that is important. You should use a carb that closely matches the displacement of the engine, although I've mixed & matched them for years & they work good. I like the ones from the late 70's to early 80's with the round choke. If it is not an electric choke you can put the electric choke in it. That way it is compatable with almost any intake manifold.

silverstreak · 03-10-2010, 08:32 PM

If you're going for a show quality factory style restoration than you'd want a "numbers matching" carb. Otherwise, as long as the replacement carb was on something close to your engine size and horsepower level, you should be good, other than the physical differences like Wrenchbender Ret mentioned.
Even if you had the correct carb for your truck, the calibration may be off if the engine has been bored out, different cam, transmission, or rear end gears have been changed. Even if the engine is all original unrestored with low miles the calibration could still be off with the new reformulated, oxygenated, nitrogen enhanced, triple filtered, techrolene infused fuel blends we have today.

**GruntMoanCough** · 03-10-2010, 10:08 PM

x2. If you want to know everything about Q-jets, get a copy of Doug Roe's Rochester Quadrajets book.

http://images.google.ca/imgres?imgur...DeCJ7otgP93IhA

ChevLoRay · 03-10-2010, 10:29 PM

I bought an Edelbrock Performer intake and the Edelbrock 750CFM Q-Jet for my 350. I don't think you can get that carb from Edelbrock, any more. For my truck, it was great. I say "was" because it is scattered all over town while being reworked by someone else. It never failed to work like I needed it to do and it has a divorced choke, instead of an electric.

When I was rebuilding carburetors, I got to where I liked the Q-Jet's better than AFB's. The 1400 series Edelbrock carbs are AFB's in my book. I've run a variety of 4-bbl carbs on my cars over the years and I still like the Q-Jet best of all.

Stay away from the MC-series (Mod-Quads) and any that have the idle air adjusting screws contained behind a casting in the base. I don't like those that use an electronic accelerator pump, either. Just the simple Q-Jets are best.

capev86 · 03-10-2010, 10:42 PM

i have an '84 q-jet off a 350cid burb that i am rebuilding for my 72 burb. i am stuffing it full of Edelbrock parts and bits from Cliff's High Performance like bronze sleeves for the throttle shafts. also have bronze renew paint from eastwood. it will be going on the stock 307 with an edelbrock performer intake (idle-5500 rpm range) and i also want to run the '84 air box that takes a 4" tall air cleaner element. eventually i will swap my 406sbc in and the stock 350 tune worked fine on it....so nothing crazy in terms of jet size, etc is planned.

03-10-2010, 06:12 PM	#1
skillet Registered User Join Date: Sep 2000 Location: denton, tx, usa Posts: 176	Roch Carb Question As far as Rochester quadrajet carbs go, is it better(as in run better) to get the exact carb for your year(mine would be '69 auto 350) or just use something that works. I currently use a 17058213(which is for '73-'78), which seems to work good. __________________ 69 SB GMC LWB Fleetside 350, 09 Pontiac Vibe 2.4 liter

03-10-2010, 06:29 PM	#2
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,204	Re: Roch Carb Question The choke systems varied by the years. Sometimes you have to use a carb to match the intake manifold. Other then that it is the displacement that is important. You should use a carb that closely matches the displacement of the engine, although I've mixed & matched them for years & they work good. I like the ones from the late 70's to early 80's with the round choke. If it is not an electric choke you can put the electric choke in it. That way it is compatable with almost any intake manifold.

03-10-2010, 08:32 PM	#3
silverstreak Registered User Join Date: Mar 2009 Location: USA Posts: 255	Re: Roch Carb Question If you're going for a show quality factory style restoration than you'd want a "numbers matching" carb. Otherwise, as long as the replacement carb was on something close to your engine size and horsepower level, you should be good, other than the physical differences like Wrenchbender Ret mentioned. Even if you had the correct carb for your truck, the calibration may be off if the engine has been bored out, different cam, transmission, or rear end gears have been changed. Even if the engine is all original unrestored with low miles the calibration could still be off with the new reformulated, oxygenated, nitrogen enhanced, triple filtered, techrolene infused fuel blends we have today.

03-10-2010, 10:08 PM	#4
GruntMoanCough Registered User Join Date: May 2009 Location: Pemberton, BC Posts: 1,075	Re: Roch Carb Question x2. If you want to know everything about Q-jets, get a copy of Doug Roe's Rochester Quadrajets book. http://images.google.ca/imgres?imgur...DeCJ7otgP93IhA __________________ My goal in life is to be as good a person as my dog already thinks I am - Unknown

03-10-2010, 10:29 PM	#5
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Roch Carb Question I bought an Edelbrock Performer intake and the Edelbrock 750CFM Q-Jet for my 350. I don't think you can get that carb from Edelbrock, any more. For my truck, it was great. I say "was" because it is scattered all over town while being reworked by someone else. It never failed to work like I needed it to do and it has a divorced choke, instead of an electric. When I was rebuilding carburetors, I got to where I liked the Q-Jet's better than AFB's. The 1400 series Edelbrock carbs are AFB's in my book. I've run a variety of 4-bbl carbs on my cars over the years and I still like the Q-Jet best of all. Stay away from the MC-series (Mod-Quads) and any that have the idle air adjusting screws contained behind a casting in the base. I don't like those that use an electronic accelerator pump, either. Just the simple Q-Jets are best. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

03-10-2010, 10:42 PM	#6
capev86 Registered User Join Date: May 2009 Location: Eliot, Maine Posts: 1,314	Re: Roch Carb Question i have an '84 q-jet off a 350cid burb that i am rebuilding for my 72 burb. i am stuffing it full of Edelbrock parts and bits from Cliff's High Performance like bronze sleeves for the throttle shafts. also have bronze renew paint from eastwood. it will be going on the stock 307 with an edelbrock performer intake (idle-5500 rpm range) and i also want to run the '84 air box that takes a 4" tall air cleaner element. eventually i will swap my 406sbc in and the stock 350 tune worked fine on it....so nothing crazy in terms of jet size, etc is planned.



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