1970 Bronco 302 - Exhaust Manifold or Headers

[tonytony9]

My exhaust manifold is looking pretty shot and I believe I have an exhaust leak. Does anyone have recommendations for specific brands or in which direction I should go, headers or exhaust manifold? Pros and Cons to each? I like a bit of a louder truck.

 

[DirtDonk]

What do you mean by looking pretty shot? And where is the exhaust leak?
A lot of products that are better than stock bronco exhaust manifolds, but depends on what you want to do and where you wanna go from here.
You can buy stock Mustang K-code manifolds (I believe they are called), over-the-counter at most auto parts stores. Price is probably pretty reasonable and breathing should be better than stock bronco manifolds.
Fitment to the frame might be a little finicky, but a couple of members here have done it and I don’t remember hearing any reports of dire consequences.
Lots of different brands of headers out there, including ours at Wild Horses (for my usual shameless plug). Long and short, with both having their advantages and disadvantages.
But louder can be achieved by mufflers alone, if that’s all you need.
Depends on what you ultimately want to do and how much you wanna spend.

 

[Ether]

I have some for sale in the classifieds- HiPo / K-code style manifolds.

Headers: louder, put off more heat (unless ceramic) especially log tubes, more fitment issues depending on model, more flow?

Manifolds: generally easier to fit if you get the ones that are appropriate for your bronco, cooler running, more "oem" look, good for more low/moderate power builds.

 

[tonytony9]

What do you mean by looking pretty shot? And where is the exhaust leak?
A lot of products that are better than stock bronco exhaust manifolds, but depends on what you want to do and where you wanna go from here.
You can buy stock Mustang K-code manifolds (I believe they are called), over-the-counter at most auto parts stores. Price is probably pretty reasonable and breathing should be better than stock bronco manifolds.
Fitment to the frame might be a little finicky, but a couple of members here have done it and I don’t remember hearing any reports of dire consequences.
Lots of different brands of headers out there, including ours at Wild Horses (for my usual shameless plug). Long and short, with both having their advantages and disadvantages.
But louder can be achieved by mufflers alone, if that’s all you need.
Depends on what you ultimately want to do and how much you wanna spend.

I have some for sale in the classifieds- HiPo / K-code style manifolds.

Headers: louder, put off more heat (unless ceramic) especially log tubes, more fitment issues depending on model, more flow?

Manifolds: generally easier to fit if you get the ones that are appropriate for your bronco, cooler running, more "oem" look, good for more low/moderate power builds.

Thanks for the feedback. A couple notes on my end;

1. I wont be looking to wheel except on the beach, so the clearance wont be an issue from the underside. In addition, I am keeping the EB stock height.
2. I am looking to get a deeper sound with more throat to it; I current have a single pipe straight back.
3. It appears my exhaust is leaking where the exhaust pipe connects to the manifold. Only on the passenger side. They are very rusty which is what I meant by shot. Ill upload a photo of the leak location.

 

[.94 OR]

Slippery slope, frame off 10 year builds started from much less.

 

[LHardin]

If you change the manifold, you may need to change the exhaust to fit it.

 

[tonytony9]

Slippery slope, frame off 10 year builds started from much less.

If you change the manifold, you may need to change the exhaust to fit it.

Hm would you guys go with the Tom's stock manifold replacements then?

 

[Shimmy]

any of the manifolds sold by the big vendors will work. did you say you were straight piped, no muffler?
if i were wanting to stay kinda stock, id opt for a manifold and new muffler. easy peasy

 

[DirtDonk]

Hm would you guys go with the Tom's stock manifold replacements then?

I don’t think they’re stating preferences for you to follow. Simply stating facts that you might have to deal with when changing designs.
Not for the purpose of trying to dissuade you from headers or performance manifolds, but instead adding to your database for making the decision.

 

[Broncobowsher]

There is a doughnut gasket where the pipe attaches to the manifold. That might be all you need. Cast iron is pretty tough, they won't rust out. You will loose every body panel and the frame before there is the start of a true rust issue with the manifold. But cracks are a different story. Manifolds are well known to crack and leak. And the fasteners love to rust as well. But the actual manifold, rust is not an issue.

Headers won't do anything for the exhaust note you describe. That is all in the pipe and muffler. The list of variables is nearly endless.
Typical header noise is more of a tinny sound. The pipe rings like a bell.

 

[tonytony9]

There is a doughnut gasket where the pipe attaches to the manifold. That might be all you need. Cast iron is pretty tough, they won't rust out. You will loose every body panel and the frame before there is the start of a true rust issue with the manifold. But cracks are a different story. Manifolds are well known to crack and leak. And the fasteners love to rust as well. But the actual manifold, rust is not an issue.

Headers won't do anything for the exhaust note you describe. That is all in the pipe and muffler. The list of variables is nearly endless.
Typical header noise is more of a tinny sound. The pipe rings like a bell.

Ah okay thank you this answered what I was looking for. I was actually thinking very much along the lines of what you were saying here. I am pretty sure it is indeed the doughnut gasket.

To confirm, the picture below is what I believe to be the culprit. You can visibly see it moving. Need to confirm where the nearest exhaust mount is as I wonder if vibration caused the issue. The PO installed a two to one straight back to what I believe is called a cherry-bomb to a single out from the passenger side.

 

[tonytony9]

 

[tonytony9]

I don’t think they’re stating preferences for you to follow. Simply stating facts that you might have to deal with when changing designs.
Not for the purpose of trying to dissuade you from headers or performance manifolds, but instead adding to your database for making the decision.

Sure I appreciate the clarification. If I dont have to change the current manifold, I wont. Only reason I am considering is because of this leak which I believe may be the doughnut gasket. Also, if it would give the truck a more throaty, louder note. Which I am learning is more to due with the pipe and muffler.

 

[tonytony9]

any of the manifolds sold by the big vendors will work. did you say you were straight piped, no muffler?
if i were wanting to stay kinda stock, id opt for a manifold and new muffler. easy peasy

Sounds is one of the few things ill compromise on for not going stock haha. I believe PO installed a two to one to a cherry bomb??

 

[ep67bro]

The doughnut gasket is shot. When I wheeled my 67 a lot I would need to change it often. A few bucks from an auto parts store and its fixed. Stick with the stock manifolds for what you want. Go with a dual exhaust system with Flow master mufflers if you want a deeper sound. Most of the venders offer a dual exhaust system that can be installed DIY or you can go to a muffler/exhaust shop tell them what you want and they can custom build it. The stock two into one exhaust is really quite, even if you changed muffler you could make that louder.

 

[tonytony9]

The doughnut gasket is shot. When I wheeled my 67 a lot I would need to change it often. A few bucks from an auto parts store and its fixed. Stick with the stock manifolds for what you want. Go with a dual exhaust system with Flow master mufflers if you want a deeper sound. Most of the venders offer a dual exhaust system that can be installed DIY or you can go to a muffler/exhaust shop tell them what you want and they can custom build it. The stock two into one exhaust is really quite, even if you changed muffler you could make that louder.

There is a doughnut gasket where the pipe attaches to the manifold. That might be all you need. Cast iron is pretty tough, they won't rust out. You will loose every body panel and the frame before there is the start of a true rust issue with the manifold. But cracks are a different story. Manifolds are well known to crack and leak. And the fasteners love to rust as well. But the actual manifold, rust is not an issue.

Headers won't do anything for the exhaust note you describe. That is all in the pipe and muffler. The list of variables is nearly endless.
Typical header noise is more of a tinny sound. The pipe rings like a bell.

I don’t think they’re stating preferences for you to follow. Simply stating facts that you might have to deal with when changing designs.
Not for the purpose of trying to dissuade you from headers or performance manifolds, but instead adding to your database for making the decision.

Thank you for everyone's advice. To wrap up this thread, this past weekend I decided to stick with the stock exhaust manifold. I then replaced both doughnut gaskets with Fel-Pro gaskets from AutoZone. Worked like a charm, no more exhaust leak.