I have some for my HD. I came across this about a Lightning.
I dont know what our's would be but its something to think about when lowering or suspension change.
What Pinion Shims Are Right For Me?
Q: I'm putting a 2/4 drop kit on my 2003 Ford Lightning. I want to order Belltech 2-inch drop spindles to keep the factory ride and 4-inch shackle/hanger kit for the for the rear. What degree pinion shims do I need for this kit?
A: Keep in mind the lightning is lowered from the factory using coil springs in the front and leaf springs in the rear. The addition of the spindles and the hanger/shackle kit will result in an overall drop of 3/6. Typically, after your vehicle is lowered you can take it to a shop and they can measure your driveline angle and let you know what shims you will need to correct it. For this application, we recommend using a 6-degree pinion shim to correct the driveline angle. This will keep your driveline angle straight and prevent any grinding that you may experience without pinion shims.