I believe the gears in a NP435 are: 6.69, 3.34, 1.66,1.00

The 6.69:1 granny gear in a NP435 is great for pulling stumps . . . but not for much else in a street driven truck. You'll essentially be installing a 3-speed.

I had one in a 53 Chevy pickup, and never used low gear.