I had rebuilt my teralow without discontinued parts and upon assembly my oil pump cracked at the tube mount. Since I wasn't sure if it would work, I put everything together and tested it for a week. Upon belief that the tera low parts worked, I ordered a new oil pump. So needing to install it, I wasn't excited about tearing open the case a second time, so I decided to try installing without disassembling the case. The only reason the case has to be split is to allow you to align the pickup tube into the oil pump. So with some mechanics wire and a couple of screw drivers I was able to work the tube enough to pop it into the pump and feel confident that it had secured properly. After 3,000 miles of on and offroad use, I have had no problems with the pump or transfer case.
Hint: For anyone that still has a teralow, don't exceed third gear in low, the bushings will eat themselves and teralow is no longer in production for 231.