Mystery drop spindle...help

[Nuke64]

So I picked up a set of 2.5" drop spindles for my 64 Shorty step. I also purchased all new ball joints and steering components. When I went to test fit today, the lower ball joints and outer tie rod ends fit nice, but the upper ball joints are too big. The taper in the spindle measures .725" at the wide side. The 64 ball joints too wide to go through the bore, the threaded portion only goes about .25" in before the taper is too small. Any ideas? Are the 73 and up upper ball joints smaller?
Thanks in advance!