Hi guys, I recently inherited by late fathers 67 C10, the carburetor was not working so i switched it myself to an Edelbrock 1406.
i have connected most hoses where they need to go but i have a few questions on a couple of ports / fittings i see on my car.

first...my old carburetor only had 3 hoses connected to it.. the power break port in the back the fuel inlet in the left and the pcv port in the front.. which i reconnected.

now if you see the diagram there are 2 vacuum ports in front i have no idea what to do with. do i cap them or leave them open? the Timed Vacuum port or Manifold Vacuum port?

while doing some investigation



i also found the intake manifold vacuum fitting screwed into the back of the engine i think.. does this go to the carburetor? need some help as you can tell I'm not too sabby.

 

No the vacuum ports in the manifold do not connect to the carb. You do need to repair replace the cracked hose to the transmission. Just cap the open ports on the carb.

 

Thank you, i really appreciate the information. I am in the process of switching all the hoses as well.
Again, since i am not familiar which hose is the one you are mentioning? I do not see any cracked in the images i posted?

 

 

You can either cap the vacuum taps on the carb or reconfigure the hoses on the vacuum fitting behind the carb. Either way you have to cap something to avoid a vacuum leak.

Right now your distributor vacuum advance and transmission vacuum modulator are connected to the fitting behind the carb. This will work ok.

Vacuum modulator requires full manifold vacuum to operate. Distributor advance is a personal preference. I like to run it off ported/timed vacuum, others like full manifold vacuum.

Curious why you said the original carb didn't work? Was probably a QuadraJet which is a very reliable carb and easily cleaned and rebuilt.

Make sure you put some type of clamp on that fuel inlet hose. As in before the next time you start the engine.

 

Cool, thank you. I will learn one day.

 

great information, i really appreciate it. Still need to do some research on how i will run my vacuums, don't know what my best options are.

As for the carburetor honestly, it looked really beat up and fuel was coming out of the top of it.. read online and think maybe i needed to change the floaters or something like that(probably could have been easily repaired) .. however i had this edelbrock here for a while now not being used so i decided to might as well switch it for the new one.

 

Is the intake manifold a square bore and what kind of adaptor did you use for the carb mount?

 

Hmm, I guess i have a lot to learn. i was not aware that i needed an adapter kit? is it required for all instillations? i will take pictures when i get home and post them to get your opinion.

 

Spreadbore vs. Squarebore carburetors: What's the difference?

 

Appreciate the link...


Turns out i have the wrong gasket.
ill see what my manifold designed for and check if i need an adapter.....thinking of going with the spreadbore option since I mainly just use the truck to cruise.

 

So this is what I have going. Do I need a spacer or and adapter? or would a spreadbore gasket only work?

 

You have a spread bore manifold and cannot mount a square bore carb to it without an adaptor. You need an Edelbrock 2696 adapter or equivalent.

Edelbrock 2696 Edelbrock Carburetor Adapters | Summit Racing

 

As always, coming through with great info.

Just purchased this one.. will pick up tomorrow and install.

 

I'm just curious, did your truck get an Oldsmobile engine transplanted into it? If it still has the Chevy engine you may get more responses on a Chevrolet form.
As for carburetors you would be much better off sticking with the original Rochester Quadrajet and have it rebuilt. It will give you better performance plus better mileage.

 

No it did not, this is my first post ever here. I didn't realize there was different threads . My apologies.

 

Eh, no worries. There are several different Chevrolet forums you might consider joining which may provide additional information pertaining to your Chevrolet 350. There are differences between the Chevrolet 350 and the Oldsmobile 350. With that said, you learned the difference between a spread bore and a square bore intake manifold as well as the various applications & adapters to mount various carburetors onto various intake manifolds - all good. Best of luck.

 

Yes sir that is true installed the adapter switched the hoses .. started it up and took it for a cruise! Next challenge power brake booster. Thank you all for the help.

 

Glad you got it going. What’s wrong with the booster?

 

Probably nothing from what I can tell, don't really know how to check.. but same with the carburator.. I have one which was purchased years ago just never installed.. so figured might as well change it and get everything looking nice inside.

 

Post a picture of the original carburetor. May just be dirty and grimy like a lot of old QuadraJets are, and can be taken apart, cleaned and rebuilt with a new gasket kit if you want to tackle that.

Kit will include new gaskets, fuel inlet needle and seat, and accelerator pump. You do have to buy the float separately. We can show you where to find the carb numbers to order the correct repair kit.

Can ya tell we like teaching people how to do stuff for themselves? 🙂 Carburetion is one of those areas where all GM Divisions are similar.

There are several excellent Chevrolet forums like the VCCA and a couple dedicated to the 67-72 pickups. Also Facebook groups but I intentionally stay away from FB as sooner or later it attracts drama.

 

I'm pretty sure that is it, looks like it's been through some battles lol... but I already installed the edelbrock one so I think I'm just going to keep it as is unless there is a better reason I should switch back?

This page has been so helpful, I was figuring no one would reply.. but glad yall got me through the first of many challenges haha

 

There must be something you perceive as being wrong w/ brake booster unless you just pick things at random to challenge yourself.

(1) Does the brake pedal feel "hard"?
(2) Does the brake pedal feel like a "sponge"?
(3) Does the brake pedal travel all the way to the floorboard?
(4) Have you examined the brake booster vacuum line for leaks, cracks, pinholes?
(5) Does the brake booster leak fluid?
(6) Are there noises coming from the brake booster?
(7) Brake booster check valves are known to wear out - you can easily remove it and perform a simple check on it. Sometimes the check valve becomes faulty and vacuum escapes. Escaping vacuum is not a good thing.

 

I was looking at some vids online and it didn't seem to bad so I was thinking why not... but now you have me questioning myself.. I really just wanted to do it because it's old and semi rusted so I was thinking new was better.. other than that I don't really feel anything wrong with the brakes with the exception that I probably need new shoes sincei press the brake all the way down if im going high speeds it takes a bit to come to a full stop.. so maybe I should do that first before I get myself into a mess.

 

What kind of brakes are on the C10? Drum on all four? Disk front, drum rear? Probably better to start pulling wheels and checking brakes themselves before diving into brake booster unless you can identify one of the symptoms in this video.

 

I have drum brakes on all 4 tires... the only symptom that sounds similar is just the longer stopping distance but then again that could be from worn down shoes no?

 

Yes.

 

Glad you agreed, honestly would rather rebuild the drum brakes than change the booster.. will advise how that goes

 

Advice on disassembly of drum brakes. Make liberal use of your phone camera. Take a picture of each component (e.g. springs, etc.) you remove. During re-assembly you can validate your assembly/installation via your photos.

 

Smart.. smart... saves me a couple.post here asking where each spring goes lol

 

I'm sure it won't surprise you how often questions arise w/ regard to which way the springs &/or clips are attached.

 

With drum brakes, do one side at a time and leave the other side for reference on how things go back together.

 

Another great tip! Thanks man. Will be tackling this next weekend I'm thinking.