bigedpa - after doing a bit of research and snagging a screen grab of one of your other pics in your
Truck Parts Wanted ad, I think you may have what you need with the existing upper and lower axle collar mounts, less the removed helper spring and brackets and associated U-bolts.
In looking in a 1929-46 Chevy Master Parts Book, the diagram for the rear axle spring setup shows it without the aux spring pack pieces, with the U-bolts mounted across the springs instead of parallel to them as seen with the helper spring packs.
Looking at the U-bolts spec'd for your '46 (same as the 1941-42 AK/BK 1/2 tons) and considering eliminating the aux spring packs, you will need new U-bolts to match the specs given for GM# 602509. Those will need to be installed as shown in the marked up screen grab to secure your axle/housing brackets to the springs. However, you will have to allow for longer U-bolt length when adding lowering blocks, so be sure to add length to the legs of those U-bolts.
Hope this is helpful.
