Chain driven aluminum cased. 2.61:1 low range (better then a 203 or 205 in the low range area). Slipyoke rear output.
I run one in my truck and have since day 1. The original case lasted 18 years before I rebuilt it last fall. I am now running the same case with a few new bearings.
I have no problem running this case. I like it alot and the low range allows me to crawl very well. I run a mild 350 with MPFI which makes pretty decent power. I rock crawl though so my case never really see's the high RPM outputs of a mud runner or things of that nature. I like the case and think it is a good case.
You must make sure that you have a skidplate so you don't samck it on a rock otherwise you will crack the case. I had a custom crossmember/skidplate built by 4x4 Iron.
Don't let everyone scare you about a slipyoke rear output. As long as you don't have insane rear flex you should be fine. I run 5" lift, 35" tires, and a 14bff. I still run stock rear driveshafts. The 14bff move the pinion forward about 1" over stocks so I didn't need to lengthen my driveshaft. For the lift I added a 4* taper to the rear axle and I get no vibrations.
I am locked front and rear and so far so good. I don't have alot of time in on the rocks yet but next wheeling season will be the true test of the cases longevity. I am not really worried about it though. It should do just fine.
Harley