Header for six cylinder

[[]V[]AXX]

http://www.summitracing.com/parts/HED-99610/?image=large

I was wondering if anyone had used one of these headers before? If so, will it fit a J10, or is this CJ only territory? My original exhaust manifold is cracked, and is the smog/air injection type anyway. I can get a used manifold that's in good shape really easy. I just wanted to know if there is any real noticeable power or mpg boost with these. This is for FL, and I'll build my own exhaust system, so no cats on this truck. I'll be using the factory 2 bbl intake also.

[freeincolorado]

I don't know if it'll work or not, but check out Clifford Performance. I think they specialize in inline engine stuff.

[tgreese]

What year is your engine? If '80 or earlier, you can use the 81-on manifolds. The later exhaust manifold is botl lighter and smooteher than the earlier manifold. And, you keep the advantages of iron manifolds.

I'm not a big fan of headers (hot, noisy, fragile, leaky ...) but if you want headers for an inline 6, the 6-to-2 design is preferred. Use dual exhausts all the way back. Unlike a V8, the tubes of an inline 6 can be grouped to two groups of three for an even exhaust pulse rate. This will give a power boost over a 6-to-1 design.

JMO - I would not spend a lot on headers until I had exhausted (pun intended) all of the junkyard mods available for the 4.2L. These include manifolds, ignition, carburetion, and the 4.0L HO head. I'd look into a cam, and a less restrictive exhaust, and the various stroker recipes, before I thought about a header. If you go with the 4.0L head, the 258 header won't fit anyway, and the 4.0L has its own factory (and aftermarket) headers.

<edit> I left out the various junkyard fuel injection setups available for the 258. Lots of options here, ranging from multiport injection from a 4.0L, to various low-buck throttle body solutions. Lots and lots of junkyard stuff out there for 258s.

[Cecil14]

That looks real similar to the Clifford 6-1 header, which will NOT fit in our rigs. I had one and without serious modifications to the header itself (or different motormounts entirely) there's no way to squeeze it in there...simply will not go.

Personally...not a big Clifford fan...their stuff costs way more than it's worth. I'm with Tim on this one...stick to the cheap available parts. LOTS of stuff to do on a 258 before you buy expensive aftermarket stuff.


aa

[[]V[]AXX]

Yeah, another guy on here has a post selling a clifford intake and exhaust. I was looking at Clifford's site, and it seems that you really can't run their exhaust without the intake too. I was looking to keep the Carter BBD for a while, because this truck is probably gonna get a propane conversion. The truck is a 79 J10 with it's stock engine. When I got the truck, it ran fairly well. It just leaked oil out of every possible place that it could leak oil. I pulled the pan and decided to rebuild after getting a look at the main bearing surfaces. It had so much dirt ingestion damage, the old man musta been runnin it without an air filter for years. I'm not really interested in the 4.0 head, because this one is all set. I actually spent extra on the head to have bronze guides installed since the valve guides were all way out of service limit. (Extra only being about $50) The Hedman 4 into 2 is a bit cheaper than this one, but I don't think it will fit with the way it comes down in the front. http://www.quadratec.com/Assets/Images/24277/24277-th.jpg.'

So, the 81 and later 4.2 liter manifold is better than the stock one on this? Does it flow better or something? If so, do you know where I could get one? I could order one from the parts house, but that's as much as a set of headers. Also, do you know if it would work with my '79 model two bbl intake?

When I rebuilt it, I installed a Crane Powermax cam. It's fairly mild, but advertises good fuel mileage with minor bolt on's. The exhaust will be free flowing since I'll be using a straight thru design muffler and I'm goin to run it up as a stack instead of out back. I'm just looking for the best flow possible without major intake side changes at this time.

So, a header isn't really worth it, you're sayin?

Also, with the 4.0 head, is it just higher compression ratio or does it have better port flow too?

[Cecil14]

"Free flow" anything on a 258 is kind of an oxy-moron. lol The head design is terrible so even with a good intake and exhaust manifold you'll only get so much. The 4.0L head isn't really any bump in compression (that I've ever head anyway). The ports are just designed way better. They sit a bit higher and are far more open, so you get a lot better flow.


aa

[TPICherokee]

1/4 flange on an inline six is about 1/2 what it should be especially the way they mate on with the intake...

[tgreese]

V[]AXX']...
So, the 81 and later 4.2 liter manifold is better than the stock one on this? Does it flow better or something? If so, do you know where I could get one? ...
The manifolds from 1981 on do not have the 4-bolt flange between them. The intake is aluminum and the exhaust is obviously lighter and smoother. I can't give you any numbers re how much better the newer exhaust manifold is compared to the older style, but from its appearance it would have to be better.

The manifolds are a junkyard item, or eBay, or from a WTB ad here or on other Jeep sites. I've had good luck with WTB ads on my local Jeep/4x4 forum.

[babywag]

Just went through obtaining newer parts for my dad's '79 w/ a 258.
The stock '79 stuff was in BAD shape, and tough to find replacements.

I picked up a used CJ intake for $35 , and the matching exhaust manifold for another $35.
The exhaust manifold was bent, so wound up buying a new one on fleaBay for $66.

Had to modify the power steering bracket a 'bit, but they bolted right on.
Throttle linkage was a different story.
'79 stuff not even close to working, we wound up buying a Lokar throttle cable setup for another $70.
Also installed a motorcraft 2bbl @ the same time.
Overall pretty pleased with the end result.

I also debated a header/intake upgrade, but the prices:eek:.

[tgreese]

I have manifolds from an '85 CJ on my truck, and used linkage from another 258 CJ or Wrangler... not sure what year. If you get the newer bracket/bellcrank and rod, it bolts up using an accelerator cable from an 81-on 258 FSJ.

[babywag]

I have manifolds from an '85 CJ on my truck, and used linkage from another 258 CJ or Wrangler... not sure what year. If you get the newer bracket/bellcrank and rod, it bolts up using an accelerator cable from an 81-on 258 FSJ.

CJ's are uber-rare in the yards around here! I have never seen one in 9 years.
Happy with the Lokar set-up...eliminates all the funkyness of the stock set-up.

[[]V[]AXX]

Well, my intake is iron, and looks like the newer manifold won't fit, so I guess I'll be buying the old one from this guy down here. I gotta fab up a cover plate for the EGR port and get bolts to plug the air injection ports. I gave up on the header after seeing one today on a CJ5 down here. He used his stock intake and had stacks of washers up against the flange to hold it on. He's complaining of leaks too. I appreciate the info, folks.

[Cecil14]

Honestly if you've already got a 2bbl BBD on there grab a set of 80's manifolds. You'll want both, not just one or the other. They are a lot better, and lighter, than the 70's stuff. Just make sure you get the throttle bracket/linkage and you can get a throttle cable from BJs.


aa