60 Inch Axle Spacing
All production - 1 3/4 Inch end holes on PL-1 and 1 3/4 Inch end holes on PL-3
Use pair codes to identify springs that are similar except for the U-Bolt plate (JP)
Noncurrent (NC) production use square bend U-Bolts with a spring steel U-Bolt plate (JP)
Current (C) production springs use a semi-round bend U-Bolts with a cast U-Bolt plate
Conversion to current production design springs is recommended to improve spring clamping