I just converted my truck from 2wd to 4wd. My truck is a 2000. When I made the swap I didn't realize the gem I had(a 1998) was different so I had a suprise of the windshield wipers running when they wasn't turned on. I went to the junk yard today and picked up a gem for the correct year and installed it and the truck now goes into 4wd but when I went to drive it I experienced some weird problems that I believe could be due to the fact that I have rabs and I think the gem must be 4wabs. The speedo was jumping clear up to 60mph and it acted like it was kicking into neutral. So here's the question.

Is the gem different for rabs and 4wabs?
Follow up question....

Will I have to get a different gem or covert my truck to 4wabs to make it work?