• Notice for iPhone users: DO NOT use the image size reduction option when uploading photos to the forum. This causes portrait images to post as landscape. We have added a warning to the image insert pop-up as well.

CJ8 304 c.i. dual exhaust.

V

Vintage Barry

New member
City
Severna Park
State
MD
I just purchased a CJ8 that has a 304. The exhaust is wasted. I'm not looking for noise. Dual. Any ideas where to look and what to avoid? Thanks for any input, Barry
 
Avoid glass packs if you don't want noise. Do you have stock manifolds or headers? Exit at the back corners will be quieter than side exit before the rear axle and will cost more also.
 
Thanks for your reply. I have stock manifolds but I'm not opposed to headers. Who sells a good kit for duals or should I go to a muffler shop?
 
Vintage Barry said:
Thanks for your reply. I have stock manifolds but I'm not opposed to headers. Who sells a good kit for duals or should I go to a muffler shop?
Click to expand...
You’re into the custom exhaust world with this. If you’re not going to DIY, it’s time to find a good exhaust shop. Decide what you want for manifolds/headers and then get to the shop.

Find one that does a lot of custom/rod work. That’s where you’ll get something solid. A local Jeep club would be helpful for recommendations.
 
Yeah. I'll go to my local shop and bring my wallet. They do great work. Any thoughts on headers, manufacturers or stay with exhaust manifolds?
 
Man I remember back in 1986 driving my buddies CJ7 with a 360, headers, glass packs and side pipes. WOW! Used to drive it between the buildings where we "bought" beer from and I'll never forget that! He's gone now from ALS but I have lots of good memories like that with him!
 
Now that's what I'm trying to avoid. A nice purr and semi quiet inside. My days of rattling windows and teeth are over.
 
I daily drove a '78 CJ7 with a 304 for 5-6 years. I drove it on 300+ mile trips, too. When I bought it it had fender well headers and glass packs. That lasted about one month. I put stock exhaust manifolds and an OEM "Y" pipe, stock muffler and single exhaust out the rear like factory. I loved it. It was quiet, yet you could still tell it was a V8. No performance drop.

When the Jeep was retired to trail duty, and the engine was rebuilt/built, I installed short headers and dual exhaust/Flow Masters out the back. This was between the two extremes. But, if I'm being honest, stock manifolds and a single 2.5" pipe is all a stock 304 needs. The dual exhaust also adds a bunch of crap to an already tight platform. Just my opinion.
 
How about some pics! I want my next Scrambler project to either have the 304 in it or transplant an AMC V8 into one with a 4-banger.
 
That's good info. I'll probably go that route. I'll post some before and after pics. Thanks again for the feedback. Barry
 
My Scrambler had duals on the 304 when I bought it. After I restored it, I went back to a single 2.5" exhaust. I had a shop do the exhaust as a stock Y pipe would hit the front driveshaft. They ran the pipes back on either side of the trans/t-case then merged them behind the t-case. See picture. I have a Flowmaster Super 44 muffler. I think it sounds a lot better and performs better then dual exhaust.

20230406_171509.jpg
 
Last edited:
One of the guys on here told me how he did dual exhaust. He moved the 15 gal tank over to the center so the tail pipes could go on each side of it. I liked that idea so that is what I've done on the two Scramblers with 304s that I'm building now. Grabbed a picture just before backing the chassis under the body. The exhaust goes all the way back and turns 90 degrees and out the sides. One has headers and the other has manifolds. The one with manifolds will probably be more quiet.
 

Attachments

  • IMG_0005 (26).JPG
    IMG_0005 (26).JPG
    160.2 KB · Views: 17
  • IMG_0005 - Copy (4).JPG
    IMG_0005 - Copy (4).JPG
    173.5 KB · Views: 17
  • IMG_0006 - Copy (5).JPG
    IMG_0006 - Copy (5).JPG
    194.5 KB · Views: 17
laffman said:
My Scrambler had duals on the 304 when I bought it. After I restored it, I went back to a single 2.5" exhaust. I had a shop do the exhaust as a stock Y pipe would hit the front driveshaft. They ran the pipes back on either side of the trans/t-case then merged them behind the t-case. See picture. I have a Flowmaster Super 44 muffler. I think it sounds a lot better and performs better then dual exhaust.

View attachment 112885
Click to expand...
Did you keep the catalytic converter on or did you remove it? Barry
Kim Dawson said:
One of the guys on here told me how he did dual exhaust. He moved the 15 gal tank over to the center so the tail pipes could go on each side of it. I liked that idea so that is what I've done on the two Scramblers with 304s that I'm building now. Grabbed a picture just before backing the chassis under the body. The exhaust goes all the way back and turns 90 degrees and out the sides. One has headers and the other has manifolds. The one with manifolds will probably be more quiet.
Click to expand...
 
Vintage Barry said:
Did you keep the catalytic converter on or did you remove it? Barry
Click to expand...
It was already gone when I bought the 8 and it had dual exhaust already. I didn't add it back on when I have the single exhaust put on.

Here's a picture I found of my duals from the teardown. They kicked the pipes to the outside of the frame at the rear axle and straight back.

20170121_152744.jpg
 
You must log in or register to reply here.
Back
Top