‘73 Cj5 Exhaust Manifolds

Need some pics of a true center dump driver side exhaust manifold for a 1973 CJ5. Currently have leaky and loud outside the frame headers to side dumps. Want to make the transition back to factory manifolds. I see a lot of driver side manifolds for sale new but I want to be sure they are the same as original. Exhaust routing pics would be awesome too.

If anyone has a used set for sale I’d be interested.

Thx
C3pilot

 

I recently did the same swap back to factory manifolds from the fenderwell headers. I can get you some pics tomorrow.

Mike

 

Im unaware of a pre-bent 2-1 exhaust for the 304. I had a local shop build me a nice stainless 2-1. Tub is pulled so I can get you a photo tonight.

I recommend a 2-1. Makes better low-mid torque, and doesnt take up so much real estate between the rails. I do not recommend routing the exhaust below then outboard of the frame rails. Thats a good way to crimp them shut when going over an obstacle, if you do stuff like that.

 

Ya I can’t seem to find a pre-bent 2-1 for a ‘73 CJ5 with the 304. Spoke to a muffler guy about doing the job the other day. $650-700 was the quote. Didn’t include manifolds nor do they put manifolds on. That price includes a cat converter, I’m tired of the exhaust smell.

 

Wow, thats plenty to charge. I think mine was something like $350-$400. I provided the muffler and the manifolds were on the engine.

Ah! I see that includes a cat. Ballpark correct then. Cats are pricey.

 

The $650-700 seems high to me.

 

I do have a muffler I could supply a Magna flow

4 x 9 OVAL 11226

It’s a straight through, not sure that I want that much noise.

 

Converter won’t fix the smell.

 

Don’t think it’ll help with the smell? I’ll say it definitely needs carb tuning as I think it’s running rich. Don’t want to start trying to tune it with all the exhaust leaks though.

I’m not an exhaust expert, or an expert on pretty much anything for that matter, but I’ve read that cats can help with smell. The muffler shop said the same thing. What have you found that will help with smell? I’m considering have the exhaust dump behind the driver rear tire.

 

Salvage yard said that they had some original CJ5 manifolds for $250 (total not installed). Sounds pricey to me.

 

Good exhaust out the rear and as tuned as you can get it. The cat will make rich exhaust smell like rotting eggs. And add cost to the pipes.

 

As I recall - All the AMC V8 exhaust manifolds are the same for the 304-360-401 from the beginning through 1979. In 1980, the left-hand side manifold changes for the wagons and trucks (goes to driver drop and becomes a "log" manifold) but the CJ continues the same to the end of the V8 CJ in 1983 (?). The earliest manifolds will have no air injection ports, but you probably won't find those. $250 sounds like robbery to me - new ones should be cheaper than that. You can look at car-part.com but I would expect to pay ca $50 for the pair from a commercial yard. You can likely find them cheaper private party; try the Wagoneer sites like www.ifsja.org and www.fsjnetwork.com or maybe www.jeepforum.com

Omix-ADA 17624.13 Left Exhaust Manifold for 70-91 Jeep Models V8 Cylinder | eBay

Exhaust Manifold Right for 1972-1991 Jeep CJ SJ Omix-Ada 17624.12 | eBay

A 49 states '73 had no convertor. Pointless to put one on if it did not come with it. Get the mixture and advance right using the original devices and it will be a lot cleaner. Look in your TSM for the devices that were originally present.

 

You should be running an oil with some ZDDP since you likely have flat tappet cam. Some say ZDDP will harm a cat. And lack of ZDDP may harm your cam.

Debunking the Urban Legend of ZDDP

 

If you have the original Motorcraft carburetor, they often have a bad power valve. Backfire can ruin the valve. Take the power valve cover off (requires removing the carburetor) and if there is gas in there, the valve is kaput. This will make them run very rich all the time. Just about any new-old car with a carburetor will need the carburetor rebuilt.

 

It has a Holley 4 barrel on it....

Not sure what size but I’m sure it needs attention. It’s electric choke that overall runs fairly well. It does backfire during shifts so I’ll follow up on the power valve. Thx for the heads up!

 

It's probably just set up wrong. Easier to run rich than to tune it right.

The older Holleys can have the same problem as the Motorcrafts, since they have the same type of power valve. Newer Holleys have an additional ball valve in the vacuum passage that guards against backfire damage.

The Holleys can run well, but they are not known for working well on the trail without modification. Lots about this in old posts if you search.

 

Awesome, I’ll search up some carb mod post to see what can be gleaned. My thoughts are to get all leaks (exhaust and intake) sorted and then start tuning the carb. Doubt this Jeep will serve any “heavy” trail duty.