Mitsu pump only outputs about 2.2GPM which is a lot less then 3.5 for GM. The hoses and tubing for PS matches that flow and is fairly small size like 5/16 (8mm) or smallter. GM prob is using 3/8. You might want to upgrade stock hydraulic lines for larger stock. Although steering box would still be a problem.

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!)