The answer is a qualified yes if you buy the Kubota/Landpride unit designed for low flow tractor systems.
SA20
The spec's for your tractor say 6.4 gpm.
Sometimes, on older machines this number is misleading if you have power steering as the PS flow is included in the total hydraulic flow.
Watch this video on the SA20..
Post Hole auger
Unless you have a lot of holes to drill, hiring someone to do the work makes more sense $ wise as getting into hydraulic systems complete with third function valve quickly gets expensive when making these systems work on older tractors.
Dave