Since Strokers are the topic......
In an M880 doing a lot of towing, a full ton 205 would be my preference along with the full ton rear drive line and differential yokes. The dana 44 up front is okay if you're not doing anything crazy off road. If you install lockouts, put a mini spool in it. You can engage the right hub for road driving in four wheel drive. If it gets ugly, lock in the left hub. And don't forget the grease fitting for the front hubs. If you upgrade from the grease fitting hub axle, you can install an ‘85 and up CAD type axle and install the cable kit that engages the left drive line along with the mini spool. That lets you leave both hubs locked for winter traveling and then you have four wheel drive and left axle lock on demand from the drivers seat.
@Moparpuller, that's a good looking pull truck in your avatar. What kind of combination you running there?