KH Discs vs 73+ Discs

IIRC, there is a very small increase in track with the KH system, over the 10" drums.
IIRC, the 73up single piston set up, is also a bit wider than the KHers.
I'm going by memory here.

your memory is not good. the width is the same for disc and drum, 73 and up is wider. Unless I'm wrong???