Semocoachworks!
I am sure someone will correct me if I'm wrong, but hydraulic was the only option I am aware of for 1962. The clutch operates off of the brake master cylinder which, if empty, will cause the clutch to fail.
Also, a 1962 4x4 Suburban is a treasure in almost any condition. Congratulations on ownership of such a find.
Have a great evening,
-Jeannie
6066 GMC Club