6,000 to 8,000LB Axles (3 Inch Wide Springs)
1000, 2000, 4000, and 7000 Series - Front
1400 through 1652 (1987-2012)
2554 through 2674 (1989-2002)
4500 through 4900 except 4X4 and 6X6 (1989-2002)
7100 (1989-2000)
6,000 through 8,000LB axles only
These axles use 3 Inch wide, 50 Inch long springs
Models with front frame extensions use 4X4 and 6X6 model springs