Why would you need to tap into gearbox?
Just cut high pressure line in half, braze on standard hydraulic fittings, and you are set. That's how I connected my winch. My biggest concern would be whether pump produces enough flow. I would dare to say not.

92 SR, 285/75R16 Yoko MT ARB locker GAST compressor AirLift 1000 MM10500 Snorkel custom rear bumper
02 Montero LS died protecting the master
08 PowerWagon (stock!)