New clutch setup won't disengage

Sure, but that requires removing the pedal and re-welding the spacer (that lines up with the original hole). The spacer is about 1.5" tall, thick-wall tubing which gives the proper offset from the pedal to the clutch master. I figured drilling one hole in the fork would be simpler...

Wrong! That damned fork is hardened, or at least made from some extremely hard steel alloy. It looks just as shiny as the day I bought it, and laughs at my drillbits (even titanium nitride coated ones). So I sloooowly ground my way through with a small die grinder and a round carbide burr, then enlarged the hole to slightly over 5/16" so the pull cylinder rod doesn't bind. It's about 1/2" closer to the bellhousing than the notch where the fork return spring sits, or about 1-3/4" from the center of the original fork hole.

The pedal is now noticeably stiffer, which means it has more fork travel as I calculated. I need to adjust out a bit more free play tomorrow but I feel confident it will work properly now. (My Isky rocker arms are at the machine shop being narrowed, so I can't try a live test for a while).