Carb Gasket
 

In the process of getting my 70 cst going for my sone, we are at the point of starting the engine. After setting up in the garage for 20+ years. We pulled the carb to go through it clean it up get the old gas out etc. When I pulled the carb off of the intake I noticed the gasket and riser plate did not seem right. Been a few years for me, since I have tore into a SB. But does this gasket and plate look right setting on the intake. I am running a Carter 4bbl.

Re: Carb Gasket
 

It’s hard to tell, but it might be an adapter plate to go from the stock spread bore intake to a square bore. Is the intake oem?

Re: Carb Gasket
 

Yes it is the intake is original, as far as I can remember

Re: Carb Gasket
 

Looks like you have a square bore Edelbrock carb on a spread bore intake manifold. I would ditch the idea of running an adapter and just pick up a decent square bore intake manifold. It will work best and have the best performance. Couple hundred and a few hours of work.

Re: Carb Gasket
 

Yup, this is exactly what I did this past winter. Definitely worth the effort

Re: Carb Gasket
 

If motor is mostly stock I would ditch the Carter square bore and source a quadrajet myself.

Re: Carb Gasket
 

If you don't want to buy anything right now and that type of gasket is sealing at the carb and at the intake I would just trim the portion of the gasket that is covering the ports on the intake. That would get you better flow into the engine. The carb and intake are miss matched, but if it ran before and you were happy with it you can leave that set up as is.

Re: Carb Gasket
 

If your carb is a square bore...they have adaptors that will transition the carb to the spread-bore intake. They are affordable and found in most AZ, O'Rielly's, etc. I have one in my truck that has an OEM spread-bore intake and a square bore Edelbrock. They do add about 3/4" to 1" rise in the carb which may effect air cleaner clearance and any hoses that would attach to it.

Changing the carb or the intake would probably be the best thing to do, but the adaptor route will be the cheapest and will be fully functional for a mild built motor. It may even add some slight performance by insulating the carb a bit more from the motor heat. This slight improvement is over just cutting up a gasket to make it quick an easy.

Tip: My adaptor came with a threaded port in the back for the vacuum line to the brake booster...that will need to be drilled out before it will work. But, my carb had that fitting too, so I just used the one on the carb and left the adaptor undrilled.

Re: Carb Gasket
 

Hey Sick 472,
That's where Im confused I have a Summit racing mega store 15 mins from the house. And I have been told that what I have is normal and I have been told what I have is not normal. Problem is the truck has been sitting in my garage for 20+ years and honestly I don't remember how it ran. Just so happens my son works at a Auto Zone and I have him checking on this adapter

Re: Carb Gasket
 

You need an adaptor like this. They work either way. Just flip it over.




https://www.performance-world.com/Ca...ter-p/2066.htm

Tell your son to search for mr. gasket or transdapt name.

By the way the dark areas on your spacer indicate the carb was running rich or flooding a bit.

Re: Carb Gasket
 

Since I'm totally confused on what I have here are some pics. I have more if anyone needs them. Again I don't know if I have a spread bore or a square bore?

Re: Carb Gasket
 

That's technically a "square bore". Take a look at a Q-Jet or Thermo-Quad. They are technically spread bores. Even some old Carter AFB carburetors had larger secondaries. It gets confusing when people lay a label on a lot of stuff, and this carb is a case in point. It could go either way, but I'd call it square bore, personally.

Re: Carb Gasket
 

Buy a Quadra jet and be done with it . :chevy:

Re: Carb Gasket
 

Thanks for the info, I think i found one on Jegs.

Re: Carb Gasket
 

Hey Steeveedee, That's where I'm confused, cause when I ask the guy at Summit he said it was a square bore because of the bolt pattern, but when I returned the adapter he had sold me, the next guy said no its a spread bore. And what I had would work.

Re: Carb Gasket
 

Nothing sounds like a Quadra jet , :chevy:

https://www.youtube.com/watch?v=21NRsuVPrqQ

https://www.youtube.com/watch?v=88c-3NYMsvI

Re: Carb Gasket
 

I guess it depends on whether you have the adapter right side up or upside down. The videos GoM posted are of a Q-Jet (obviously) and that is a spread bore. If the guy told you that the adapter that fit the carburetor baseplate you posted is a spread bore, he is misinformed.

Re: Carb Gasket
 

They sound WAY better under load.

https://www.youtube.com/watch?v=3666SqW9Xi0

Re: Carb Gasket
 

Here’s two gaskets side by each to compare spreadbore to squarebore.



https://www.speedwaymotors.com/Edelb...SABEgL-avD_BwE

Re: Carb Gasket
 

[COLOR="Red"]Hey, I want to thank everyone for the feedback and input.
geezer#99 and everyone else who recommended the carb adapter, found one tried it and it work like a champ.
After rebuilding my first carburetor, and a little valve adjustment the ole Chevy fired up today, and ran like a champ. Man I gotta say what a good feeling to hear that old truck after 20+ years sitting ion the garage.
Thanks again for the feedback..... [/COLOR]

Re: Carb Gasket
 

Do you have any stumbles under heavy throttle from idle? I just pulled an adapter like that off of a project truck that had a holley on it. The adapter was about 1/2" thick and made some wicked flow issues. The holley worked flawless but the motor didn't run well. I pulled a qjet out of atleast a 5 year storage and installed it. The motor came alive instantly and power and driveability was way up. Even sounds like a different motor. This thing should have liked the holley better but the adapter and intake killed it. Just a thing to look out for. The front barrels where about 1/3 obstructed by the adapter. I bought the truck this way incase anyone questions my sanity. Good luck.

Re: Carb Gasket
 

Hey burnin oil.
I have not, BUT I have only just got the engine running last weekend. It has been in my garage for 20+ years. And we are in the process of getting set up for son, he wants a project truck, he now has one.

Re: Carb Gasket
 

Back in my trooper days, we'd turn over the air cleaner to get that sound on the dispatch tape. Dispatch would get so mad because it was so loud. Motor pool would turn em back correct, we'd turn em over again.This went on for years

Loved to run 130 with that sound.

Apologies for the side convo on the Qjet sound.

Re: Carb Gasket
 

And I am still flipping them to this day.

Re: Carb Gasket
 

You want a real howl, try running 2 quadrajets on a dual quad intake.