M1009s are Blazers and just have 10 bolts.
M1008, M1010, M1028, and M1031 all are Dana 60 and 14BFF. All are regular cab 4x4 trucks. M1008 is a pickup, the others are sometimes too. IIRC, M1010 are ambulance bodies, M1028 are communications (and have trac-lock front diffs, IIRC), and M1031 are chassis cabs. There were also some duallies too. I think (not 100% but I think) that the duallies had NP205s.
