I drove a GMC 550 with a NP for 4 years. The 1 to 2 shift is awkward, but If you don't untrack big loads you don't need 1st gear. I had straight air, but no spring brakes. All I had was an E-brake on the transmission which was worthless because the lining got oily. I parked her in 1st gear and carried 4x4 blocks to chock the wheels.
