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Old 09-20-2018, 08:35 PM   #1
bozly
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'71 air cleaner & manifold help

I am new to older vehicles and looking for a bit of guidance. I was lucky enough to pick up my grandpa's 1971 C10 with 350/350 combo.

Goal: install headers and have a shop fab up a dual exhaust system.

Problem: I am unsure of 2 items that are coming off the air cleaner and believe they will give me a problem when in install headers. So, I am looking for help identifiying them and finding a work around.

Yellow arrow: what is this yellow tube that runs from the air cleaner to the exhaust manifold. How does this come into play when installing aftermarket headers?

Green arrow: looks like a vacuum line that runs from the air cleaner to the side of the carb. If i need a new air cleaner to fix the above green arrow issue how does this vacuum line come into play with the carb?

Any help or suggestions is greatly appreciated.



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Old 09-20-2018, 08:56 PM   #2
geezer#99
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Re: '71 air cleaner & manifold help

The yellow arrow points to the hot air tube. It’s function is to supply hot air off the manifold. You need heated air during the warm up time when you first start your motor.
The vac hose to the green arrow is a manifold vac source. The vacuum pulls a flapper door shut in the air cleaner snout. Once the motor starts to heat up, there’s a coil inside that cap that overcomes the vacuum and the flapper opens to let fresh air into the snout.
Your headers will eliminate the hot air tube. The air cleaner flapper will always stay shut ( no heat to heat the coil) and the only air to your carb will be thru that small hole when you remove the heat tube.
You can run it with headers and a different air cleaner but you could have first start(cold) problems until the intake warms up.
If you’re creative you can remove the shroud on the manifold and adapt it to headers and keep your air cleaner working like normal.
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Old 09-20-2018, 09:01 PM   #3
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Re: '71 air cleaner & manifold help

Not to be rude, but why headers? That looks like a stock engine, so you're not likely to see any performance gain. But what you'll get in return is more noise inside the cab, periodic leaks, and more heat in the engine compartment.

I would go with the dual exhaust without the headers if it were my truck.

Oh, and welcome to the board.
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Old 09-20-2018, 09:08 PM   #4
bozly
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Re: '71 air cleaner & manifold help

Quote:
Originally Posted by geezer#99 View Post
The yellow arrow...
Thank you for so much information in one post. Honestly really appreciate that!


Quote:
Originally Posted by truckster View Post
Not to be rude, but why headers?

I would go with the dual exhaust without the headers if it were my truck.
Well, to be honest, I have no idea other than I figured it was the best idea. You are right, though, it is stock and likely stay that way for a few years before I can get to a rebuild.

Should a muffler/exhaust shop be able to make a dual exhaust that connects to the factory manifolds? It currently has what I would consider a Y pipe to single exhaust that exits driver rear or axel.

Thank you for the info too!
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Old 09-20-2018, 09:13 PM   #5
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Re: '71 air cleaner & manifold help

Beat me to it! Man, I type too slow..
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Old 09-20-2018, 09:45 PM   #6
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Re: '71 air cleaner & manifold help

Quote:
Originally Posted by bozly View Post
I am new to older vehicles and looking for a bit of guidance. I was lucky enough to pick up my grandpa's 1971 C10 with 350/350 combo.

Goal: install headers and have a shop fab up a dual exhaust system.

Problem: I am unsure of 2 items that are coming off the air cleaner and believe they will give me a problem when in install headers. So, I am looking for help identifiying them and finding a work around.

Yellow arrow: what is this yellow tube that runs from the air cleaner to the exhaust manifold. How does this come into play when installing aftermarket headers?

Green arrow: looks like a vacuum line that runs from the air cleaner to the side of the carb. If i need a new air cleaner to fix the above green arrow issue how does this vacuum line come into play with the carb?

Any help or suggestions is greatly appreciated.





Welcome to the board!

Looks to be in nice condition. If that was my grandpas truck I would just put the duals on the stock manifolds and drive it the way it is for a while. Don't be in a hurry to make a bunch of changes to it until you make sure it's what you really want to do. How about a few more pictures?

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Old 09-20-2018, 10:34 PM   #7
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Re: '71 air cleaner & manifold help

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Welcome to the board!

Looks to be in nice condition. If that was my grandpas truck I would just put the duals on the stock manifolds and drive it the way it is for a while. Don't be in a hurry to make a bunch of changes to it until you make sure it's what you really want to do. How about a few more pictures?

LockDoc
Solid advice I think.

Nothing wild done to it yet. I just gave it a CLR bath to remove a bunch of surface rust, new lower molding as the orginal stuff was really damaged, and a new rear bumper. It is a very unique color combo of green and yellow, but I dig how ugly it is.

Edit: I need better pictures of the paint after it was cleaned with CLR. It really smoothed it out and removed a ton of surface rust. Paint is still in bad shape but it blends much better than the original pictures present with. The last 2 pictures in the album show what the paint looks like now.

here are a few pics.

https://imgur.com/a/hpV2x6e

Last edited by bozly; 09-20-2018 at 10:41 PM.
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Old 09-20-2018, 10:40 PM   #8
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Re: '71 air cleaner & manifold help

If you haven’t owned it long and/or driven it much, you might be better leaving it stock as is until spring.
Cooler temps and how old carbed trucks react to it can be a disappointing experience.
That color combo was referred to as ‘slime on lime’! LOL!
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Old 09-20-2018, 10:52 PM   #9
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Re: '71 air cleaner & manifold help

That heat tube only serves to help it warm up fast. Has no function during cold start. I generally run the open element air cleaners and headers and my trucks start right up year 'round. I agree with others who say hold off, at least till you get better aquainted with it. You may decide to leave it be.
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Old 09-20-2018, 11:50 PM   #10
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Re: '71 air cleaner & manifold help

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Originally Posted by bozly View Post

Should a muffler/exhaust shop be able to make a dual exhaust that connects to the factory manifolds?
Absolutely. They can make a complete system from the manifolds back.
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Old 09-21-2018, 06:43 AM   #11
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Re: '71 air cleaner & manifold help

Welcome, aboard, Looks like gramp pa did you good. Clean original truck, nice score. Exhaust shop can make whatever you want, original or dual 2.5 stainless all the way back. Original cast iron manifolds are decent, and low mantanence. I seasoned mine, couple threads about treating them, season them like a cast iron skillet. Post some more photo's when you get a chance.
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Old 09-21-2018, 09:55 AM   #12
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Re: '71 air cleaner & manifold help

I found a way to go around the Heat tube and that Flapper in the air cleaner.Most guys Don't run the Stock carb.They run a holly or a Eldalbrock Carb.I know they stop using the Manuel Choke.But on the Dash behind the cluster the Hole for the choke cable is still there they never took it out.On my 1972 3/4 ton I drilled the3 hole for the choke and put it throw the Dash Basel and put the Chrome screw on peace on the cable it looks factory.

That will help with your cold starts in any part of the country.Manuel chokes always work
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Old 09-21-2018, 10:06 AM   #13
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Re: '71 air cleaner & manifold help

What do you gain with a manual choke? If it has the original intake & Qjet, then the original choke works fine. My 72 has never had any choke issues since I bought the truck in 2003. Push gas to the floor once, turn the key and it starts and idles perfectly. Kick it off fast idle after a few seconds and drive away. Never stalls, never stumbles. I wouldn't fix something that ain't broke.
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Old 09-21-2018, 10:07 AM   #14
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Re: '71 air cleaner & manifold help

this is the bracket for the side of the edalbrock Carb for the choke Cable This is how it fits on them carbs
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Old 09-21-2018, 10:15 AM   #15
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Re: '71 air cleaner & manifold help

Most people change carbs and they pedal trick no longer works cus most people trash can the Rodchestor carbs.Some times it dose not work like a fine wine.The Manuel Choke put you in control of warming up your truck.I've gotten in my 1972 a few times on a cold day.I do the same thing But i pull out my choke and i set it and forget it.

When i worked for this trust company and i hauled trusses for houses I drove a 1966 3 ton bobtail with a 283 4 speed with a spliter in it.I go and check all the fluids and i stop on the pedal 1-2 times while Depressing the gas pedal i pull the choke.Now that that time this truck had a 2 BB carb from Rod Chester.

But it worked flawless I could let it sit in the yard for 15 mins and it warm that truck right up
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Old 09-21-2018, 10:23 AM   #16
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Smile Re: '71 air cleaner & manifold help

You've come to the right website for some good advice and insight on your truck.

First, the move to dual exhaust is an good, easy idea if you can do it economically....no harm, nice to have and helps with tuning the engine or finding a missing cylinder/spark, etc.

As for changing the stock ramhorns over to headers....I would say reconsider this.
It is very unlikely, if not completely unlikely, that you will notice any difference at all in power or performance with your engine.

The original ramhorns provided pretty good flow for these motors from the factory...the headers advantage only shows up on higher performance engines and higher rpms'....so this might be time, effort and cost with very little if any payback.
...apart from the underhood noise and leaks, lol.

More pics of the truck!!.....but based on the minor engine pics...it looks to be pretty original and pretty nice.

All good
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Old 09-21-2018, 11:21 AM   #17
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Re: '71 air cleaner & manifold help

Bozly's 2nd picture clearly shows a Qjet under the air cleaner. Although a lot of people may have trashed Qjets in the past, many are finding and reinstalling them today. For my money, I'll take a Qjet all day compared to any aftermarket, especially on a stock truck. And if we take a poll of users on this site, I'll bet most would agree.
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Old 09-21-2018, 11:23 AM   #18
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Re: '71 air cleaner & manifold help

Q-Jets are awesome. Why spend $$ on something just because? If you have $$ to burn, there are a lot of other things you can get to freshen the truck up.

The stocker the better and the more reliable. Unless you are building a street machine with a 11.5:1 bottom end for the street, leave the motor alone, maybe upgrade to HEI and install a taller K&N that raises the lid of the air cleaner about 1/2".

Exhaust recommendation: Leave the manifolds, but go with a 2-1/2" exhaust and a cross over pipe.
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Old 09-21-2018, 11:39 AM   #19
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Re: '71 air cleaner & manifold help

Quote:
Originally Posted by LockDoc View Post
Welcome to the board!

Looks to be in nice condition. If that was my grandpas truck I would just put the duals on the stock manifolds and drive it the way it is for a while. Don't be in a hurry to make a bunch of changes to it until you make sure it's what you really want to do. How about a few more pictures?

LockDoc
I agree 100% on putting new exh. system on with old exh manifolds. Being new to classic vehicles, headers can be a headache, even to a veteran car guy.

The quadrajet you have now can be saved. www.cliffshighperformance.com can sell you e kit and all the parts you need to calibrate your carb to today's gas, and the parts are ethanol resistant. His parts are no where near any of the el cheapo prices for kits on ebay, but you get what you pay for...every time!!!
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Old 09-21-2018, 11:44 AM   #20
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Re: '71 air cleaner & manifold help

I'm solid with QuadraJets. Can't beat them. On my '71 wrecker the Edelbrock manifold on it had no choke well so no way to run factory choke. I installed a manual choke set-up same as stsalvage, in stock location. On my '72 I don't have the rod from carb to manifold. I depress the pedal and it starts. It runs on high idle till it smooths out (a minute or more), and I tap the pedal to get normal idle. Been that way for two years now. I just have to watch touching the pedal when it's warm or it sets the choke and it won't start. I've ordered the rod a couple times and have gotten the wrong one. Just doesn't seem to be a priority. And this truck runs headers and an open element.

I just prefer headers. I have seen no negative results to change my mind. Maybe some engines I've had didn't benefit from them but they didn't hurt it either. Maybe it's just cool factor or just how I came up through the '60s and '70s when it seemed to be the thing to do. We choose what we like, whether a big benefit or not... just like custom wheels people spend heaps of money on that re held on by lug nuts, a tire mounts to them, and they spin while the truck is moving, same as factory wheels most trucks don't run.
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Last edited by special-K; 09-23-2018 at 06:34 AM.
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Old 09-21-2018, 11:52 AM   #21
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Re: '71 air cleaner & manifold help

I love the color combo. It's not funky at all
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Old 09-21-2018, 04:21 PM   #22
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Re: '71 air cleaner & manifold help

I didn't really see any questions about the Quadrajet from the OP, but I would definitely keep it. There was never a better carb made, in my opinion.
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Old 09-22-2018, 06:59 PM   #23
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Re: '71 air cleaner & manifold help

Welcome to the board. I'm not too far from you. Adding dual exhaust is a great idea. As suggested, add a H-pipe or a X-pipe. Don't listen to the nay sayers about headers. The only time you'll have problems is if you buy crap headers. Good quality headers won't leak any more than a set of stock manifolds will. Get a set of Doug's or Doug Thorley Tri-Y headers as they're meant for low rpm where you'll be driving at. They're spendy, but well worth it. However, I agree that you should stick with the manifolds at the moment and just add the duals. Get to know the truck for awhile and save for good headers.
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Old 09-25-2018, 01:50 PM   #24
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Re: '71 air cleaner & manifold help

On a stock engine rams horn exhaust manifolds are very adequate and can easily run dual exhaust. The rams horn is one of the best flowing manifolds that was made. The old Vette's used a little bigger version. Keep it stock unless you are adding other stuff. The rams horn is adequate even with a mild cam and better intake. Headers tend to push the power band up a bit and without the other stuff to take advantage of them you may actually harm your driveabilty.
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