The drive train on the M1009 is a 1/2 ton drivetrain that probably has been beefed up a little for the military. Any GM with six lugs is in the half ton family. It would need eight lugs to have the 3/4 ton drivetrain. That being said actually gross vehicle weights differ alot more than the designations suggest. I have an F350 that is rated to 12,000 lbs gvw. With the truck weighing 6,500 That leaves 5,500 for payload. My math says over 2 3/4 ton capacity on a 1 ton chassis. My point is they have the 1/2, 3/4, and 1 ton ratings to give them the model lines but the individual trucks may have more capacity that the family in which it belongs. Most of the familys have similar drive train components. I have a dodge with a 3/4 ton rated front drive axle for plowing while it is a 1/2 truck. I still has 5 lugs of the 1/2 ton family. The drive train of the M1009 is a 1/2 ton chassis they may have rated at 3/4 ton because of stronger components but it is still a half ton truck.