Installing Caster Shims is fairly easy if you have tools, tall jack stands, and a floor jack. You need the truck high enough for the axle to drop down and hang with out hitting the ground. The frame should be supported with jack stands, floor jack under the axle. Loosen the the u-bolt nuts on one side and lower the axle once the nuts are off. It's highly recommended to change u-bolts once they are removed due to stretch, they are a soft grade material. The caster shim goes between the axle mounting pad and the leaf spring with the thickest part of the shim at the back, ( thin end pointing towards front bumper ).
Be sure the leaf spring locating center pin aligns with the hole in the shim and the hole in the axle when going back together. Your shims should 1 3/4" wide.

This is a good time to wire brush the axle pad and clean out the mounting hole. While the axle is off the springs, check the spring bushings and shackles for any side to side or up & down movement. They should all be tight, well greased, and nuts snugged up. If you find loose bushing, nows the time to replace them.

Reinstall the u-bolts, jack up the axle to sandwich the shim between the spring and axle, tighten the u-bolt nuts, follow the recommended torque spec for the diameter of the u-bolt thread. Google bolt torque if you don't have a service manual.

Do both sides, drive a few days, then retorque the u-bolts.

Start out with 4 degree shims.

For a front sway bar, any of the venders will have one, they are all the same, look for a price you are willing to pay. Installing one is easy, most have detailed instructions included. While installing the caster shims is a good time to install the sway bar. Look for vintage truck specific venders.

1937 Chevrolet Inline-powered Streetrod