Exhaust Questions

I just purchased a 1975 CJ5. Life-long Arizona vehicle, straight as an arrow, 38,000 original miles (verified). It has the 232ci 6cyl. and the T-16 tranny( I believe ) and besides new tires and wheels and a new bestop full softop it's all stock and roll.
I need to replace the muffler as it seems to be all used up. I was considering doing some mods as long as I was having the muffler replaced. I was considering a few things: header, high flow catalytic, and an muffler upgrade. I have heard considerable amounts of do's and don'ts and alot of contradictory advice concerning this and I was looking for some sage advice from some people who know.
Consider that I am not looking to tremendously boost Horsepower or turn this into a screamin', mud-boggin', rock crawlin' beast or anything. I just thought I could muster a couple of extra horses, a little better fuel economy and make life a little healthier for my 232.
Any advice?

 

JOSHUA,
Why bother putting on a catalytic (converter) ??? Is it required in your state for a 1975 utility vehicle??

SPW

 

Hi Joshua - I'd agree with SPW, you don't need a CC. IIRC no 1975 Jeep models used CCs in any state.

There's not a lot to do with a 232 exhaust. It's a single pipe and a muffler. If you want a little more power, you might go with a free-flowing aftermarket muffler, though the stock style muffler will be quietest.

I looked up your app on Walker http://www.walkerexhaust.com/ and it seems that all the parts are available. If it were mine, I'd buy the whole system from Walker (or one of their competitors) and install it. Exhaust systems take a terrible beating in rocky terrain, so being able to change out standard parts will be an advantage. You should use double hangers and double clamps (turned 90 degrees to each other) when you install it. Use the STEEL manifold gasket (aka donut) available from FelPro. Your FLAPS can help you with these parts.

I would not put too much hop-up effort into a 232. They are very reliable, but underpowered. You'd be better off building a 258 or 4.0L to replace it rather than trying to upgrade. hth!

hth! (and welcome from Boston!)

BTW there is no T-16. It's a Borg-Warner T-14. Also, if you want some cheapish hop-up ideas for the 232/258, just ask.

 

I believe that '75 CJs in California did have cats.

 

While the 75 CJ5 may have had cats in Cali, it isn't required to keep them until 76 model year.

 

Could be, though my '75 258 CJ-6 delivered in Placentia did not have one ... maybe 304s?

 

Thanks for the input! How about the question of a header. Is it really worth it?

 

Other than being fragile, hot, leaky, noisy and expensive, they are fine. And these problems are magnified on a Jeep because of the abuse the exhaust system must take.

I think you're much better off with a cast iron exhaust manifold, and the 81-on 258 manifold is much smoother than the earlier manifolds. You'll have to use the 81-on aluminum 2V intake, and that will require a carburetor change. These later manifolds are what I have on my truck.

 

X2 on the header. I have headers on my 75 that are a couple of years old and shot. Plus header might interfer with your steering shaft. The more you work on it the more parts pile up and you end up sulking because your not driving it......I made that mistake..

 

Thanks to all for the sage advise on the exhaust issues. I found a place locally that had the complete Walker exhaust system I needed, found that I did not even have (or need) a catalytic and kept the stock exhaust manifold, running 2 1/2" from there to the tail. I would have taken some unecessary and expensive advise probably if it were not for the generous info submitted on this forum. Thanks again!

 

yep
first year required in Calif (no 49 state)
both S6 and V8s