M923 vs M813

[acesneights1]

Rather than start my own, I'm gonna bump this. I am facing the same dilemma right now and every point made here is valid.
Really I LOVE the look of the 813 with Super singles. It is the baddest azz looking truck IMHO. I am just not in love with the Sprague TC. I did a boat load of reading here today on them and am a bit concerned about the reliability although they do seem relatively easy to repair if they do break(The T138 TC).
May have to resort to the highest decision making authority available....

 

[Oldworldtenacity]

I always did like the look of an M813, but when it came down to me buying a truck...I had to get the more rare M923A2 Frankencab with a heavier reinforced safer cab and air ride seats. I think it is the most menacing looking of the 5 tons(other than full up armored models) and I get a lot of comments driving around that it looks extra beast with the cab. If you can find one with a winch with the extended bumper....they really look menacing with the bigger cab and hood.
Also, the Cummins Turbo 8.3 has by far the most potential for cheap power upgrading and I manually shift the Allison a lot on hills and it does way better because the shift points are not that great stock. M923A2 is defnitley faster.
The airbrakes are better on the M923A2 as well. I would not like having a truck with a smaller cab than the M923A2 frankencab, so you better find the models you are considering and sit inside them or drive and get a feel for it before you buy.

 

[Oldworldtenacity]

Also, with regards to off roading...I don't think there is much difference with either truck....they will both get stuck up just as bad as the other lol.

For serious off roading either truck needs a locker in the front axle if not all axles...IMO.