Going back to factory intake and carb - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bbarbeau · 03-21-2021, 08:33 PM

My '72 with a 350 has had the intake and carb changed to an Edelbrock. I'm thinking about changing it back, not that it doesn't work right, I'm just want it to be closer to factory.

Is there anything I need to look out for when looking for parts? Are intakes the same for car and truck applications etc?

Thanks!

MAC71Cheyenne · 03-22-2021, 10:42 AM

Can't answer that but interested is hearing from those that can....

MARKDTN · 03-22-2021, 11:14 AM

Yes, stock Q-jet intakes should be easy to find. Really should fit '69-85 305 and 350 truck, van, Camaro, Impala, Nova, Corvette (to '81), Chevelle..... Some of those would be factory aluminum, especially later ones. Some might have more coolant holes that you need, but any would work before the center holes to the head changed angle about 1986. '66-68 would also fit but have a oil fill hole in the front that would need plugged.

**StingRay** · 03-22-2021, 11:19 AM

Just watch out for some of the older stock 4 BBL intakes that need a metal shim under the carb as the exhaust heat passages can come up through the top of the intake and the shim blocks the exhaust from entering back into the intake. Great carb heat for clod climates but a little too great for any kind of performance. I found one of these as a kid and was a bit puzzled by it but with all the right parts it worked fine. Id stay away from the later intakes with EGR and set up for divorced choke unless you are planning on using a a later divorced choke Q-Jet. I'd just paint the intake a swap the carb. The later divorced electric choke Q-Jets are an excellent carb.

Bbarbeau · 03-22-2021, 01:56 PM

Thanks everyone, that's really helpful! I'm assuming that stuff like this is plentiful but now I can look for the right things.

Divorced choke: what year did they start doing those?

54blackhornet · 03-22-2021, 03:06 PM

I removed the original cast iron intake on my 71 GMC. Installed an aluminum Edelbrock Performer with the provision for the divorced choke. Original QJet on top. This setup I believe is superior to stock. I have the original intake hanging on the shop wall.

Bbarbeau · 03-22-2021, 03:17 PM

Oh interesting! Were you having trouble with the factory set up or looking for better performance? Just curious.

Quote:

Originally Posted by 54blackhornet

I removed the original cast iron intake on my 71 GMC. Installed an aluminum Edelbrock Performer with the provision for the divorced choke. Original QJet on top. This setup I believe is superior to stock. I have the original intake hanging on the shop wall.

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BROWN 70 · 03-22-2021, 03:45 PM

x 2 post 6. lighter and more port velocity. good luck, BROWN 70

palallin · 03-22-2021, 05:37 PM

I went the other way and replaced a stock intake with an aluminum one and a Q-Jet with an Edelbrock. I, too, am now thinking of going back. The weight difference is absolutely trivial in anything except a full-on race application. I got better mileage with the Q-Jet. Only two things are keeping em from acting on my plan:
1) I need to collect the parts, and I'd want to have the carb seen to by someone who knows his business
2) In a K truck, the distributor is so wretchedly close to the firewall that pulling it is no fun.

One of these days, however, I will get up the gumption and tackle the job. It will give me a change to clean things up and seal a few leaks, too.

**MikeB** · 03-22-2021, 06:15 PM

This thread brings back memories. When I got my 69 C10 in 1989 it had a stock 307. I bought a used Q-jet manifold for $10 that turned out to be from a 69 350. Then bolted on an NOS Holley Economaster 450 CFM Q-Jet replacement. Found it in a dusty, beat-up box in the back of a parts store. Those guys just about gave it away! Along with dual exhaust, that 307 felt like it had gained 50 horsepower. And fuel mileage actually increased by 20%.

BTW, Holley still sells Q-jet replacements, but they are totally different than the Economaster.

Bbarbeau · 03-22-2021, 07:43 PM

Your comment about the distributor got me thinking that the distributor has been changed to electronic ignition (I think it’s HEI). Is that a problem with fitting around stock parts?

Quote:

Originally Posted by palallin

I went the other way and replaced a stock intake with an aluminum one and a Q-Jet with an Edelbrock. I, too, am now thinking of going back. The weight difference is absolutely trivial in anything except a full-on race application. I got better mileage with the Q-Jet. Only two things are keeping em from acting on my plan:
1) I need to collect the parts, and I'd want to have the carb seen to by someone who knows his business
2) In a K truck, the distributor is so wretchedly close to the firewall that pulling it is no fun.

One of these days, however, I will get up the gumption and tackle the job. It will give me a change to clean things up and seal a few leaks, too.

RustyBucket · 03-22-2021, 08:29 PM

Quote:

Originally Posted by Bbarbeau

Your comment about the distributor got me thinking that the distributor has been changed to electronic ignition (I think it’s HEI). Is that a problem with fitting around stock parts?

There are inexpensive small cap HEI distributors. They come in black and look stock with an external coil.
https://www.speedwaymotors.com/Chevy...xoC5YYQAvD_BwE

palallin · 03-23-2021, 09:52 AM

Quote:

Originally Posted by Bbarbeau

Your comment about the distributor got me thinking that the distributor has been changed to electronic ignition (I think it’s HEI). Is that a problem with fitting around stock parts?

Not really. The problem is just that it practically touches the firewall. You just learn a whole new vocabulary

**MikeB** · 03-23-2021, 12:18 PM

Quote:

Originally Posted by Bbarbeau

Your comment about the distributor got me thinking that the distributor has been changed to electronic ignition (I think it’s HEI). Is that a problem with fitting around stock parts?

Not a problem on my 69 C10 with the engine mounted in the forward position. There's 3"-4" between large cap HEI and firewall.

bry593 · 03-23-2021, 01:57 PM

You'll want a 1969-1974 iron intake (should be a date cast in). These have the mounting pad for the divorced choke coil that is used on Quadrajet 70 series carbs from 1969-1974. You definitely don't want to use a 170 series carb (1975-late 80's) on an early intake and vice versa, else your choke will not work.

I do not recommend the hot air intake from 1975-1980ish. That choke style is terrible. You can convert an early 170 series carb to the later electric choke ($45), but you need to plug up the hot air passage on the intake manifold.

So, focus on finding a 1969-1974 manifold and Quadrajet. These work really well unless you buy a Quadrajet from a rebuilder. Rebuilders do all sorts of stupid things and it's a gamble. Best to buy an untouched original at a swap meet and rebuild it yourself.

When looking for a good Quad rebuilder, the main thing is to look for a downward bend at the front of the carb mounting holes. A lot of people went full shade monkey and hammer torqued the screws. This squishes the airhorn and the zinc carb body. Basically smashes it into a frowny face shape. Avoid these as they are pretty much junk.

Another common Quad issue is corrosion in the bowl/main body. Gasohol will screw up everything once it begins to decompose.

As a manifold alternative, you can pick up an old school Weiand or Edelbrock spread bore aluminum manifold. Just be sure it includes the little piece that the choke coil mounts to. Be sure to check for stripped threads and corroded water neck mount. If you paint the aluminum orange, most won't notice it isn't original.

54blackhornet · 03-23-2021, 04:57 PM

A properly set up QJet is far superior to a Edelbrock as far as mileage goes. Ask me how I know...

**Ironangel** · 03-23-2021, 04:59 PM

Cant beat the Edelbrock 2101 with a properly tuned Quadrajet...The 2101 does have the divorced choke option on it.

**Ironangel** · 03-23-2021, 05:04 PM

Quote:

Originally Posted by 54blackhornet

I removed the original cast iron intake on my 71 GMC. Installed an aluminum Edelbrock Performer with the provision for the divorced choke. Original QJet on top. This setup I believe is superior to stock. I have the original intake hanging on the shop wall.

I fully agree with this! The QJet is far more mileage friendly than either the Holley or Edelbrock carbs...

**MikeB** · 03-23-2021, 05:34 PM

Quote:

Originally Posted by Ironangel

Cant beat the Edelbrock 2101 with a properly tuned Quadrajet...The 2101 does have the divorced choke option on it.

Can't beat those tiny primaries for fuel mileage and throttle response. I don't know why we didn't see more aftermarket carbs like that.

**dmjlambert** · 03-23-2021, 09:45 PM

If you want closer to stock but don't mind a newer Quadrajet, I am enjoying my later model Quadrajet with electric choke from National Carburetors. It is model number ND4478 for 1981-86 trucks. They make remanufactured ones (that I have) and they now have new ones. I am using it on my original 1969 hot slot manifold. That is the type that StingRay mentioned above and I use the special composite and metal gaskets with it, and the heat passages have been plugged on mine. So if you end up with one of those it is workable.

http://67-72chevytrucks.com/vboard/showthread.php?t=762751

http://67-72chevytrucks.com/vboard/showthread.php?t=765690

.

**StingRay** · 03-23-2021, 10:47 PM

Yup that one. Seems like yesterday but it was 40 years ago. Smoking price they have on Q-Jets.

Quote:

Originally Posted by dmjlambert

If you want closer to stock but don't mind a newer Quadrajet, I am enjoying my later model Quadrajet with electric choke from National Carburetors. It is model number ND4478 for 1981-86 trucks. They make remanufactured ones (that I have) and they now have new ones. I am using it on my original 1969 hot slot manifold. That is the type that StingRay mentioned above and I use the special composite and metal gaskets with it, and the heat passages have been plugged on mine. So if you end up with one of those it is workable.

http://67-72chevytrucks.com/vboard/showthread.php?t=762751

http://67-72chevytrucks.com/vboard/showthread.php?t=765690

.

Bbarbeau · 03-24-2021, 09:12 PM

Quote:

Originally Posted by StingRay

Yup that one. Seems like yesterday but it was 40 years ago. Smoking price they have on Q-Jets.

Wow, thanks for the responses! Lots of detail there that is so helpful. I do wonder if getting to some swap meets would be the easiest/cheapest way to get parts likely.

So National Carb - that’s a really good price. I saw that Rock Auto had some too but I don’t know where they were coming from.

**MikeB** · 03-25-2021, 09:55 AM

I wonder how many mass market rebuilders install throttle shaft bushings and address float bowl leaks. I'd get in touch with Cliff Ruggles, a guy who literally wrote the book on Q-Jets to see what he has available.
https://cliffshighperformance.com/

Bbarbeau · 03-26-2021, 10:07 PM

Oh cool, thank you! That’s awesome, I had no idea, that looks like a must have book too.

Quote:

Originally Posted by MikeB

I wonder how many mass market rebuilders install throttle shaft bushings and address float bowl leaks. I'd get in touch with Cliff Ruggles, a guy who literally wrote the book on Q-Jets to see what he has available.
https://cliffshighperformance.com/

toolboxchev · 03-27-2021, 02:37 AM

Quote:

Originally Posted by Bbarbeau

My '72 with a 350 has had the intake and carb changed to an Edelbrock. I'm thinking about changing it back, not that it doesn't work right, I'm just want it to be closer to factory.

Is there anything I need to look out for when looking for parts? Are intakes the same for car and truck applications etc?

Thanks!

have been watching this for about a week now. machinist tells me those factory intake actually have a curve in the machined surface that mates to the heads.

I looked at my factory intake upon my last top end rebuild 10 years ago. Whatta ya know????

I still have the factory carb from 1970 in near perfect condition to rebuild. I am looking at an 84-86 carb from Cliff if you know what I am after.

PM me for more details.

03-21-2021, 08:33 PM	#1
Bbarbeau Registered User Join Date: Oct 2020 Location: Kingston, ON Posts: 67	Going back to factory intake and carb My '72 with a 350 has had the intake and carb changed to an Edelbrock. I'm thinking about changing it back, not that it doesn't work right, I'm just want it to be closer to factory. Is there anything I need to look out for when looking for parts? Are intakes the same for car and truck applications etc? Thanks!

03-22-2021, 10:42 AM	#2
MAC71Cheyenne Registered User Join Date: Aug 2020 Location: Mount Pleasant Iowa Posts: 303	Re: Going back to factory intake and carb Can't answer that but interested is hearing from those that can....

03-22-2021, 11:14 AM	#3
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,129	Re: Going back to factory intake and carb Yes, stock Q-jet intakes should be easy to find. Really should fit '69-85 305 and 350 truck, van, Camaro, Impala, Nova, Corvette (to '81), Chevelle..... Some of those would be factory aluminum, especially later ones. Some might have more coolant holes that you need, but any would work before the center holes to the head changed angle about 1986. '66-68 would also fit but have a oil fill hole in the front that would need plugged. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

03-22-2021, 11:19 AM	#4
StingRay Senior Member Join Date: Mar 2000 Location: Saskatoon,SK,Canada Posts: 2,476	Re: Going back to factory intake and carb Just watch out for some of the older stock 4 BBL intakes that need a metal shim under the carb as the exhaust heat passages can come up through the top of the intake and the shim blocks the exhaust from entering back into the intake. Great carb heat for clod climates but a little too great for any kind of performance. I found one of these as a kid and was a bit puzzled by it but with all the right parts it worked fine. Id stay away from the later intakes with EGR and set up for divorced choke unless you are planning on using a a later divorced choke Q-Jet. I'd just paint the intake a swap the carb. The later divorced electric choke Q-Jets are an excellent carb. __________________ Saskatoon, Saskatchewan Canada

03-22-2021, 01:56 PM	#5
Bbarbeau Registered User Join Date: Oct 2020 Location: Kingston, ON Posts: 67	Re: Going back to factory intake and carb Thanks everyone, that's really helpful! I'm assuming that stuff like this is plentiful but now I can look for the right things. Divorced choke: what year did they start doing those?

03-22-2021, 03:06 PM	#6
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,250	Re: Going back to factory intake and carb I removed the original cast iron intake on my 71 GMC. Installed an aluminum Edelbrock Performer with the provision for the divorced choke. Original QJet on top. This setup I believe is superior to stock. I have the original intake hanging on the shop wall. __________________ 71 C-20 07 Magnum RT AWD

03-22-2021, 03:45 PM	#8
BROWN 70 Registered User Join Date: Aug 2010 Location: central oregon Posts: 145	Re: Going back to factory intake and carb x 2 post 6. lighter and more port velocity. good luck, BROWN 70

03-22-2021, 05:37 PM	#9
palallin Registered User Join Date: Jul 2002 Location: St. James, MO Posts: 1,239	Re: Going back to factory intake and carb I went the other way and replaced a stock intake with an aluminum one and a Q-Jet with an Edelbrock. I, too, am now thinking of going back. The weight difference is absolutely trivial in anything except a full-on race application. I got better mileage with the Q-Jet. Only two things are keeping em from acting on my plan: 1) I need to collect the parts, and I'd want to have the carb seen to by someone who knows his business 2) In a K truck, the distributor is so wretchedly close to the firewall that pulling it is no fun. One of these days, however, I will get up the gumption and tackle the job. It will give me a change to clean things up and seal a few leaks, too. __________________ '69 Longstep K-10: 327/SM465/T-221/Closed Knuckle Dana44/12-bolt.

03-22-2021, 06:15 PM	#10
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,408	Re: Going back to factory intake and carb This thread brings back memories. When I got my 69 C10 in 1989 it had a stock 307. I bought a used Q-jet manifold for $10 that turned out to be from a 69 350. Then bolted on an NOS Holley Economaster 450 CFM Q-Jet replacement. Found it in a dusty, beat-up box in the back of a parts store. Those guys just about gave it away! Along with dual exhaust, that 307 felt like it had gained 50 horsepower. And fuel mileage actually increased by 20%. BTW, Holley still sells Q-jet replacements, but they are totally different than the Economaster. __________________ Mike 1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

03-23-2021, 01:57 PM	#15
bry593 Registered User Join Date: May 2016 Location: Oklahoma Posts: 188	Re: Going back to factory intake and carb You'll want a 1969-1974 iron intake (should be a date cast in). These have the mounting pad for the divorced choke coil that is used on Quadrajet 70 series carbs from 1969-1974. You definitely don't want to use a 170 series carb (1975-late 80's) on an early intake and vice versa, else your choke will not work. I do not recommend the hot air intake from 1975-1980ish. That choke style is terrible. You can convert an early 170 series carb to the later electric choke ($45), but you need to plug up the hot air passage on the intake manifold. So, focus on finding a 1969-1974 manifold and Quadrajet. These work really well unless you buy a Quadrajet from a rebuilder. Rebuilders do all sorts of stupid things and it's a gamble. Best to buy an untouched original at a swap meet and rebuild it yourself. When looking for a good Quad rebuilder, the main thing is to look for a downward bend at the front of the carb mounting holes. A lot of people went full shade monkey and hammer torqued the screws. This squishes the airhorn and the zinc carb body. Basically smashes it into a frowny face shape. Avoid these as they are pretty much junk. Another common Quad issue is corrosion in the bowl/main body. Gasohol will screw up everything once it begins to decompose. As a manifold alternative, you can pick up an old school Weiand or Edelbrock spread bore aluminum manifold. Just be sure it includes the little piece that the choke coil mounts to. Be sure to check for stripped threads and corroded water neck mount. If you paint the aluminum orange, most won't notice it isn't original. __________________ 1971 C20 Custom Deluxe, HT383, 4L80E, 3.73 Locker, 4 Wheel Discs

03-23-2021, 04:57 PM	#16
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,250	Re: Going back to factory intake and carb A properly set up QJet is far superior to a Edelbrock as far as mileage goes. Ask me how I know... __________________ 71 C-20 07 Magnum RT AWD

03-23-2021, 04:59 PM	#17
Ironangel Senior Member Join Date: Feb 2010 Location: Falls City, Nebraska "100 Miles From Nowhere" Posts: 2,219	Re: Going back to factory intake and carb Cant beat the Edelbrock 2101 with a properly tuned Quadrajet...The 2101 does have the divorced choke option on it. __________________ Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American"

03-23-2021, 09:45 PM	#20
dmjlambert Senior Member Join Date: Apr 2016 Location: Cypress, TX Posts: 3,561	Re: Going back to factory intake and carb If you want closer to stock but don't mind a newer Quadrajet, I am enjoying my later model Quadrajet with electric choke from National Carburetors. It is model number ND4478 for 1981-86 trucks. They make remanufactured ones (that I have) and they now have new ones. I am using it on my original 1969 hot slot manifold. That is the type that StingRay mentioned above and I use the special composite and metal gaskets with it, and the heat passages have been plugged on mine. So if you end up with one of those it is workable. http://67-72chevytrucks.com/vboard/showthread.php?t=762751 http://67-72chevytrucks.com/vboard/showthread.php?t=765690 . Last edited by dmjlambert; 03-23-2021 at 09:58 PM. Reason: Correcting link

03-25-2021, 09:55 AM	#23
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,408	Re: Going back to factory intake and carb I wonder how many mass market rebuilders install throttle shaft bushings and address float bowl leaks. I'd get in touch with Cliff Ruggles, a guy who literally wrote the book on Q-Jets to see what he has available. https://cliffshighperformance.com/ __________________ Mike 1969 C10 LWB -- owned for 34 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 23 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!



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