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!

Re: Going back to factory intake and carb
 

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

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.

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.

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?

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.

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



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Re: Going back to factory intake and carb
 

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

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.

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.

Re: Going back to factory intake and carb
 

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?

Re: Going back to factory intake and carb
 

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

Re: Going back to factory intake and carb
 

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

Re: Going back to factory intake and carb
 

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.

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.

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...:metal:

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.

Re: Going back to factory intake and carb
 

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

Re: Going back to factory intake and carb
 

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.

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/a...1&d=1524875946
http://67-72chevytrucks.com/vboard/showthread.php?t=762751


http://67-72chevytrucks.com/vboard/a...1&d=1467966489
http://67-72chevytrucks.com/vboard/showthread.php?t=765690

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Re: Going back to factory intake and carb
 

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

Re: Going back to factory intake and carb
 

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.

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/

https://cliffshighperformance.com/wp...book_large.jpg

Re: Going back to factory intake and carb
 

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

Re: Going back to factory intake and carb
 

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.