I am sticking with the stock xfer case from the 88, the s10 has a 4l60e so the bolt pattern should match up just fine and I keep my stock speedo drive. Main thing I'm robbing is the motor and Trans.
The truck was tbi, someone converted it to carb and I'll be going full efi when I swap the vortec in,that's why i got the whole truck so I could rob the harness and sensors too