Power Steering Box Input Shaft Size?

[David VanderVelde <dwvander@domain.elided>]

I am in need of a new power steering box, mine leaks badly and the steering is very loose.  The parts houses want to know if I have a 3/4
inch or 13/16 inch input shaft, and they will have to order the box.  This is my daily driver and I don't want to have to take things
apart twice.  Does anybody know which size input shaft is on the IH Model S-281 (Saginaw).  I do measure 3/4 inch further up the steering
column, but can't get to the actual input shaft without removing the column or box.

Thanks,
David VanderVelde
dwvander@domain.elided
Ridgefield, WA
77 Scout II
(I was asked the other day if I recently had my motor rebuild, he said it sounds really good.  I told him yes, 195000 miles ago, in 1977)