[Funky61]

Jerrspud added the link to 63gmc4X4’s thread of a clutch disc that would work. I sent my disc that did not fit back to Platinum Driveline and had them find me one from a 1996 Chevy truck 1500 with the 4.3 V6.

Here is that disc, #381066, which cross checked to 70375 and 04121.
I have it here compared to a NOS GMC 11” disc I bought awhile back.

The springs are more recessed in the newer disc and it sits flatter, but the cone is taller on the original by about 3/8”.