replacing exhaust system, need advice

I need to replace the exhaust from the manifold back. I need some advice. I am looking for maximum fuel economy, nothing else. We don't have emissions testing in WI, but I would like it to be legal in other states. I don't believe that there is a catalytic converter on my '77, and I believe the exhaust is the original. Do I need to put one on to be legal now?

 

If the car did not come with a convertor from the factory, you don't need one to be legal.

Consulting my 1977 factory service manual reprint (hint, hint), the 49-states CJ-5 with a 258 was not equipped with a CC. However, high-altitude and California vehicles were - though I can't tell you how to tell where your vehicle was delivered without the sale documents.

I wouldn't worry about it. Should it become necessary to test your vehicle in another state, and either of the cases I cite above apply, the testing database would indicate the need for a CC. A new CC would be easy to install at that time.

<edit> Also, you're in the wrong forum for a '77. No problem - the moderators may move your post - just FYI.