I lucked out. All my old ones were usable.

Dave, I called DAYTON Products Springs today.........Im working on buying the plastic pieces and steel straps, but have already been told that DAYTON may not sell individual
component pieces, but my request is getting moved up the food chain a bit..........

I have NOS Trans Am Leaf Springs (and Sway Bars) that I bought in the early 80's to install in my 70Z, but never got around to it.....These NOS GM Springs have Black Plastic Pieces with SLOTS very much the same as the DAYTON springs I have for another Camaro project...
Have ho idea when the slotted design was started at GM, but wanted to share this info
with anyone interested........

Plastic leaf spring spacers
 

I have axis to a injection mold machine .If anyone has samples of the plastic leaf spring spacers I may be able to mold some .Are there 2 types?
Mike

I have a 3D CAD .stp file of the 1st design that I can send you. The second design with the slotted oval is currently made so shouldn't be as much an issue for folks to buy. The material is polypropylene. IM me if you are interested.

I have a guy that has a waterjet that cuts horn parts for me. I bet he can cut some straps.

These are the clamps I got from DAYTON Spring Products
along with new Black Plastic Squares and the Rubber Pieces