I purchased a set of helper springs for 2000 Extended Cab Longbed work truck. After disassembling the springs, I find out the centering pin head will not got through the helper spring and into the axle mount hole. It's not long enough.

does anyone know where I can get a longer headed center pin? I've tried PEP Boys, and the internet. Seems no one makes them. Why would the directions tell me to get one if it's not long enough?

Jon