Headers and exhaust kits

[danray48]

I know I really need to spend more money, My 79 CJ7 AMC 258 i6 / 4.2l 6, wants a new header and exhaust kit. Does anyone make a nice complete exhaust kit to either go out the side, or straight out the back with duel exhaust. I've seen the split header, but not much of anything else, that would be easy. Thanks.

 

[Petescj]

Ive never run across a complete kit front to rear for a CJ7 . Not sure what Transmission you have but automatics tend to make it more difficult. Most people are going to tell you to install the header yourself then take it to a muffler shop like Midas.

 

[Old Dog]

I'm with Pete on this one. A good muffler shop will make what ever you want.

 

[danray48]

Thanks for the replys. That sounds like the best. There is a good shop nearby. It's a manual 3 speed.

 

[rr41mag]

I have a dual collector header and ran my own exhaust. It comes out on both sides and stops just forward of the rear wheels with turnouts. The cherry bombs are kinda loud though.

 

[jerry1847]

I picked up a pacesetter set for my AMC 258 i6 / 4.2l on CL for 100, +75 for new install kit from pacesetter. Cant wait to install. Im planning on (already have on stock) a flowmaster super 40. Also, if you want to cheap with crush clamps, amazon has a stock walker replacement pipe for ~$35. It fit fine for me (i started with the non-cat back)

That setup + the motorcraft 2100 carb will be sweet

 

[79CJMike]

Am I to understand that Pacesetter is the best dual collector setup out there? I have a stock 258ci with a standard tranny and would like advise for a better exhaust system. I also plan to add a Weber conversion for the carburetor. Thanks, Mike

 

[Hedgehog]

Please be aware, headers are generally for straight line high RPM running. Low end torque will suffer with headers. Yes I know, it doesn't make sense. The engine breaths better and should be more efficient all around. In real life that isn't the case when it comes to good old jeepers low end torque. I admit to have headers on my Jeep, that is because the PO had the stinkin' things there when I bought it. MY jeep is pulling all the money I have right now to get her on the road. As soon as I can I will be installing the stock exhaust manifolds and having a set of header pipes made/installed.

 

[Kane]

To a certain degree you are correct. The right kind of header for the AMC 258 i6 / 4.2l would need to have very small primary pipes to keep the exhaust gas velocity high. This will keep your scavenging rate higher so the engine can breath at the lower rpm range that it lives in. Generally the stock exhaust manifold does a better job at this but a properly built header with low rpm scavenging in mind will out perform the stocker.

 

[79CJMike]

It's been awhile but thanks for the input. I've decided to keep the manifold and add a Weber conversion. I'm looking for emission plugs, some call them crown plugs, for the exhaust manifold. Any thoughts for a source? Thanks, Mike

 

[elwood blues]

I went to my local hardware store and bought pipe plugs, I think technically they're called socket pipe plugs, they look like this.

Even your big box hardware stores (Home Depot, Lowes) should carry them in the hardware section.

 

[Peanut Butter]

I just used pipe plugs for the exhaust and brass plugs for the block.