Tishomingo comes up as in Oklahoma. It's Paladin trucks. Company's posting: Product Detail
It's weird that they didn't say who they were in the CL ad.
I'm all for more J54 owners, I love mine. Got it off eBay from a fellow in Oregon. Get's 30 mpg and with lockable hubs plus overdrive that'd be more like 38 or 39 mpg. CJ3B clone. Transfer case is Dana Spicer 18 clone. Transmission is either a T90 with an additional intermediate gear or a T98 with no granny gear.
But that's off topic from the engine question. Engine is the Mitsubishi 4DR5, used in the US in Mitsubishi forklifts: 2.7L 4 cyl. Variants were used in the Mighty Max pickup. A Mitsubishi Diesel Jeep is a great option if you don't want to pay the $12000+ labor (Jeff Daniels quote) to swap a 4BT into a CJ. You won't have many options to select from unless you import it yourself. Luckily there weren't many factory options, so they're all about the same anyways, just condition.
If you're swapping a diesel into a Jeep stick with the tried and true 4BT. There's tons of info online about solving the custom things you'll have to deal with.
Just realized that I wrote all this and it's an old thread. Oh well...