[chuckies76ta]

Hi Rick. On my 76 Trans am I left them in top and bottom when I first restored the car. Later on I bought a Moser 12 bolt rear-end, and removed them all-together. I still have my muilt-leaf springs on the car. I used spacer plates from Calvert to set the springs in place. I also have a set of Caltracs on this car.
I did the same on our 68 firebird. On this car it has a 12 bolt rear-end with split mono leaf springs and a set of Caltracs. I removed the rubber spacers also. Makes it easier to set pinion angle on both cars. The only thing that is crucial in all this, is the bolt in the center of the spring needs to be retained in the center of the axle. In one of the cars I made a bushing that fit the lower bracket hole to center the leaf spring bolt. In the perch on the axle I use a spacer that accommodated the bolt in the spring, and welded the spacer in the perch. This is a link to Calvert site shown some of the lowering blocks I used.
https://calvertracing.com/product-categories/parts/
I also installed U Bolts around the axles down through the perch to the bottom plate, washers and double nuts and torqued. Hopefully this make some sense.
The other thing that is very important is the crush of the leaf spring in the perch. The bottom plate snugs up against the bottom of the perch and clamps the leaf springs and blocks in place. You want to make sure you don't bottom out the plate on the perch, before everything is torqued. You may have to install a spacer to take any slack up.