Question for the experts out there. I have been wanting to upgrade my engine since I have picked up my jeep in 07, but it is still running good so I haven't done anything to it yet. The engine is all stock, I did add a 2 inch lift to the Jeep so I could put on bigger tires on it. I eventually want to upgrade the intake and carb (go from 2 to 4 barrel), but I have decided to start with upgrading the exhaust for two reasons. One, to hopefully get better performance (would like a little more HP for street driving), and two to get that cool V8 sound.
My question to the experts: What are the best headers to get for a 304 and are they easy to install? Do you recommend doing this with the stock intake and carb (will eventually upgrade)? I am hoping to get some that fit with no modifications needed by me (I have read that in-frame headers can be a very tight fit and some require a new starter, but I would prefer in-frame as I don't want to cut holes in my fenders). I am a beginner mechanic and have never added headers so the more detailed you guys can be on what I should get, the better. Besides headers, what is recommended to put behind them. I don't want it crazy loud, but would like to get that cool V8 rumble sound (that I don't have now).
I have uploaded some pictures to try to show how much space I have available to put in the headers.
Go to "MoC's build thread"for some possible problems, page 92.
Personally I don't think there worth the effort. The factory manifolds flow pretty good. Just put some good mufflers on. You might also send MoC a PM, he can tell you more about the ones he has. Bill
I wouldnt get headers again. They are a PITA in regards to clearance issues, and they constantly need tightening. Also, you lose some low end torque with them. the stock manifolds work great.
Burch dog- I've been researching this for a while, and agree with the others; the 304 has "dog leg" ports that allow for much improved flow, so headers aren't necessary. I'm pulling stock manifolds and following what Matt did by dipping them in the etch and clean solution he got from Home Depot, then painting them. I've heard guys say the Magnaflows sound great. Rob- yours sounds awesome!
Yea, don't do headers, everything I have read on this forum and others is they don't seal well, hard to get exhaust pipes / systems to fit correctly and your not really gaining any HP to speak of, stick with the factory manifolds set up a ture dual exhaust system and put some cherry / glass packs on it if you want a little noise.
I've run headers for years on my 73 CJ 304 with no problems. Make sure you get good gaskets and install them corrrectly. Some headers come with drilled head bolts that allow you to safety wire them to keep them from backing out.
I've run headers for years on my 73 CJ 304 with no problems. Make sure you get good gaskets and install them corrrectly. Some headers come with drilled head bolts that allow you to safety wire them to keep them from backing out.
when I had headers (as well as 2 other buddies) on our amc v8's we ALL had/have problems even with good gaskets. You must just be one of the 1 in a million.
It was so bad I was tightening my header bolts every day I drove it. I even lost a few bolts here and there.
With a $25 investment (1-gal Prep & Etch, 1-can of VHT paint), a wire wheel, and some elbow grease, your factory manifolds can look like this.
I've put almost 2000 miles on these since refurbishing them, and I can honestly say they still look exactly the same. I'm very impressed with the VHT manifold paints, especially if you follow their curing instructions to the letter.
BTW, the first thing I'd do to your engine is hunt down that nasty leak and repair it. :thumbsup:
With a $25 investment (1-gal Prep & Etch, 1-can of VHT paint), a wire wheel, and some elbow grease, your factory manifolds can look like this.
I've put almost 2000 thousands miles on these since refurbishing them, and I can honestly say they still look exactly the same. I'm very impressed with the VHT manifold paints, especially if you follow their curing instructions to the letter.
BTW, the first thing I'd do to your engine is hunt down that nasty leak and repair it. :thumbsup:
Have'nt seen or heard to much on these on here, but I have the Doug Thorley tri-way headers and absolutely love them. They are pricey but well worth it in my opinion.
With a $25 investment (1-gal Prep & Etch, 1-can of VHT paint), a wire wheel, and some elbow grease, your factory manifolds can look like this.
I've put almost 2000 thousands miles on these since refurbishing them, and I can honestly say they still look exactly the same. I'm very impressed with the VHT manifold paints, especially if you follow their curing instructions to the letter.
BTW, the first thing I'd do to your engine is hunt down that nasty leak and repair it. :thumbsup:
Thanks. I get blown a lot of **** over baking parts in my home oven, but there really isn't anything too obnoxious about it. The smell isn't bad, and it doesn't linger long. And there doesn't seem to be any lasting affects on the oven.
If the OP is still on the fence about headers versus stock manifolds, (have we even heard from the OP since his original post?) here is what my manifolds look like installed.
Question for the experts out there. I have been wanting to upgrade my engine since I have picked up my jeep in 07, but it is still running good so I haven't done anything to it yet. The engine is all stock, I did add a 2 inch lift to the Jeep so I could put on bigger tires on it. I eventually want to upgrade the intake and carb (go from 2 to 4 barrel), but I have decided to start with upgrading the exhaust for two reasons. One, to hopefully get better performance (would like a little more HP for street driving), and two to get that cool V8 sound.
My question to the experts: What are the best headers to get for a 304 and are they easy to install? Do you recommend doing this with the stock intake and carb (will eventually upgrade)? I am hoping to get some that fit with no modifications needed by me (I have read that in-frame headers can be a very tight fit and some require a new starter, but I would prefer in-frame as I don't want to cut holes in my fenders). I am a beginner mechanic and have never added headers so the more detailed you guys can be on what I should get, the better. Besides headers, what is recommended to put behind them. I don't want it crazy loud, but would like to get that cool V8 rumble sound (that I don't have now).
I have uploaded some pictures to try to show how much space I have available to put in the headers.
I agree w/most respondants, I would not recommend headers instead of stock, exhaust manifolds. Years ago I owned a 304 equipped CJ5. It came w/headers and I had all the same problems already mentioned (frequent loosening, high heat) additionally, they're not configured to give you the proper, carburator pre-warming (I used the stock, Motocraft 2bbl and stock air cleaner). I ditched the headers for stock manifolds. I agree w/most respondants, I'd keep your stock manifolds and maybe invest in a high quality dual exhaust if you're dead set on an upgrade. (I used the stock "Y" pipe and was always happy w/power, and responsiveness).
when i rebuild my engine i didnt have the stock manifold and so i got headers. they were nothing buy a pain in the ***. they wouldnt stop leaking and the cj frame is too narrow for headers imo. i bought stock manifolds and love them. they dont leak so there is no more ticking the exhaust sounds better and my engine runs cooler now that there isnt all the exhaust leaking into the engine area.
I installed Edelbrock Ceramic Coated Shorty Headers #65912 over 2 years
ago on the 304 in my '79 CJ7 and have not had any problems.
Edelbrock discontinued their exhaust headers not long after my purchase.
I used ARP 1 Inch Long 5/16" Header Bolts # 100-1110 & Percy's Seal-4-
Good Header Gaskets # 66044 and a Dynomax Y-Pipe from 4WD Hardware
Part # DYN40376.
My 7 had fenderwell headers when I purchased it. See photos here.
A few years ago I looked long and hard for those. After the slow economy of 08-09 manufacturers stopped production of shorties. Even called Doug Thorley and he said that there just was not enough demand for AMC headers so they did the same and stopped production of them. I still search for them occasionally.
Thanks for everyone's response. Good info!! Rob, I like the sound of your engine, that is what I am looking for. Matt, nice work, they look brand new!!
So it sounds (no pun) like I should stick with the stock manifolds, and put something better behind them (dual exhaust). So I have a few questions:
1) Does someone have recommended parts to order that come ready that I can just bolt on behind the manifolds without and custom work?
2) I put in a 21 gallon polyurethane tank last year and I don't really have room on the passenger side for dual exhuast (see pic), is there options to run the passenger side pipe out the side before the rear tire, or route it over where the current exhaust comes out?
Thanks for all the info already provided, and thank in advance for your help!!
Well no one is going to like my response here. hahaha. I took off the high flow manifolds and went with the hooker headers. I actually found them dirt cheap on craigslist for 80$. After picking them up I realized the were 2 1/2 inch collectors. I had a set of 3 inch "race" flowmasters and wanted to go true 3 inch dual all the way back. So my solution was to cut off the 2 1/2 collector purchase 3 inch collectors and fab everything up. Everything was smooth until the install. The header flanges have almost zero tolerance on the head bolts to the block. Infact I found that the crowns of the head bolts were enough to inter fear with seating the headers. I went so far as to align the head bolts to try to clear the header flanges. This didnt work. Going for broke I removed one headbolt at a time and machined the head of the bolt down (basically remove the lip on the bolt). I had to do this for all the lower head bolts. This combined with different length allen head bolts I dont think i would offer my services for another person. It does sound mean but i know my neighbors hate me in the morning. The guys i wheel with love it. It all depends on what you do. I have alot of hotrods so this made sense to me. Talk soon
You can do what I did and center the gas tank, that is how I got mine to fit a pipe on either side. On that note, the reason I wanted them to run out where they did is so they wouldnt get messed up on the rocks, they are protected by the shackles/springs as well as the gas tank.
As far as a complete bolt in kit for true duals, I dont think it exists. Even if there was, I will take a shop made custom setup over a kit anyday. I bought my glasspacks at advance auto for about $20 each and brought them to my shop and showed him exactly how I wanted it.
It is too bad you aren't closer, I am parting my Jeep out lol
Thanks. I get blown a lot of **** over baking parts in my home oven, but there really isn't anything too obnoxious about it. The smell isn't bad, and it doesn't linger long. And there doesn't seem to be any lasting affects on the oven.
If the OP is still on the fence about headers versus stock manifolds, (have we even heard from the OP since his original post?) here is what my manifolds look like installed.
false, the 20 gallon is actually the same width as the 15 gallon. If you center the tank like I stated in my last post, you can easily fit a pipe in between the tank and the shackles on both sides.
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