Originally Posted by YIK YAKS 67 SS
The drivers side fit fine with room for adjustment of the snubber with the square u bolt.
The "square u-bolt" you reference is a safety hoop. It's not really designed to adjust the gap between the bumper and the spring eye.
I wouldn't recommend using it to get the bumper closer to the spring unless it's only a very slight amount (less than 1/4"). Doing so could put an irregular pre-load on the spring and prematurely wear it out, or damage it (or so I'm told).
Originally Posted by Custom Jim
If something like this doesn't work then moroso used to sell aluminum angle wedges and were made out of aluminum. These are used to adjust the angle that the traction bars sat and would go on the rear axle assembly/leaf spring mounts. I think they were about 3 degree wedge ?.
Lakewood and Moroso both make these shims. They can be purchased in 1* "stackable" shims, or 2, 3, and 4* shims. The can be used to either bring the bumper closer to the spring, or give you more distance.
I had to use a 4* shim for each side with my multi-leafs to get them with 1/4" of the spring eye. I like mine as tight as possible.
Another method would be to trim the bumpers...just don't get too carried away.