In looking at the resource info above, the 8 leaf spring is probably from a 3/4 ton truck. Perhaps a shade tree mechanic fix from days gone by? They both used the same length and width front springs, just 7 leaf for 1/2 ton and 8 leaf for 3/4 ton. I 'm thinking the 8 leaf right spring probably has the associated 3/4 ton bump stop retainer and lower shock mount as they are different than the 1/2 ton versions.
The shims listed for your AK are GM# 474682. It's the same part number for 1936-40 COMM & UTIL trucks (except FB and COE models), plus 1941-55.1 Series 1/2 & 3/4 tons (except D-D models). General description indicates they are 1-3/4" wide x 3-7/8" long, with a tapered front thickness of about 3/32" to 9/32" thick on the tall end. That's approximately a 2.8 degree shim wedge.
General Spring KC offers a wide variety of shims sets, to find your desired degree. They offer only 1 set that is the correct 1-3/4 wide, but that's a 4 degree set which may be too high for your needs. They do offer several other sets that are 2" wide, in 2, 2.5, and 3 degrees. You would just need to trim their width down to properly fit your springs and u-bolts. I seem to recall other previous posts where folks have done just that.
Here's the link for the
General Spring Shim listing page.