Actually, the 3.8 got the even fire hardware hardware in mid-'77, two years after GM bought the tooling back from AMC. (They had sold the Buick V6 tooling to AMC/Jeep in 1969 or 1970.) When GM first put the 90 degree V6's in their FWD cars, they had a 3.1L version as well as the 3.8L. The current 3.1's are based off of the 2.8L and there's also a 3.4L. There's also a DOHC 3.1L 60* V6 that was developed from the 2.8 family. In both the 2.8L family and the 3.8L family there are FWD and RWD/4WD variants and due to block differences, most parts don't interchange between their drive varaints.

I've got a '71 Jeep CJ-5 that came with a 225 (3.7L) V6 and researched my options before deciding it was most cost effective to get more power by swapping in a V8. I've also got an '86 Cherokee that came with a 2.8L GM V6 and is getting a SFI 3.4L from a '94 Camaro. I've also got a couple of FWD 2.8L's hanging around collecting dust/rust... anyone wants them, they can have them, free.