At work we have 2 CH 613 Mack daycabs.
'95- E7-350, Eaton 9spd, Mack rears w/4. 17s
'90- All Mack drivetrain. EM6-300, T2050 5spd.

(great for running empty and thats it), 5. 13 gears in drives.
He's looking for another Mack, but I am trying to talk him out of them again. They're reliable and tough, but hate working on them when I do. Even simple oil changes suck. Filter placement is horrible the way they are set in there. The '99 and later trucks that we have leased in the fall, that has been improved.
The ones we have, don't have a power divider lock-out switch. On these it is supposed to work like a limited slip. Works OK on the 5spd, doesn't work at alll on the other.
NO leg room. Have broken 2 turn signal switches with my knee going for the clutch.
Miss the torque of the Cummins. Big difference between a 14liter Cummins and 10-11 liter Macks.
Used to have a KW K100E (cab over). Except for the harsh ride and being a bit tiresome climbing in and out of when hauling grain (in and out alot), I really liked that old truck. Had a 400hp BC 855, Eaton 13spd transmission and rears. Power divider lock-out switch.
When we get a new truck, I'm hoping to get something with at least a 450hp engine. 350 is fine for hauling grain. It's fine for hauling cattle as long as you don't have much for a hill or a head wind. Can't get out of its own way.