Pardon me for being skeptical, but what headers does Jegs sell for the 235? I found some Gibsons for the 4.0L Jeep, but not the 235. Please correct me if I'm wrong.
I would be happier with the cast headers for one reason, heat. Bare tube headers allow tremendous heat loss. Ceramic coating helps, but the engine bay gets hot with tube headers. This not only heats up the cab, but also causes power loss due to the rapid cooling of the exhaust. The cast headers run far cooler.
For dual exhaust run 1-3/4 or 2" tubes. The smaller tube will give you slightly better low end torque, and will be more than enough capacity unless you're going to be running 6,000 rpm.
For mufflers, a pair of 24" glass packs sounds great. But I've never heard steel packs on an old six.
