It is a modified D44. There are a few posts around here describing the differences. It has to do with what carrier Isuzu used with their chosen ratio ring and pinion gears. It will affect which unit will work for you.

Also search for old posts by Peter Plotz (pplotz). He was one of the first to install an OX and did a lot of work with OX Locker to get it right.

Good Luck,
Michael