Got an old 440 which is based on a Ford 6600. Been an excellent workhorse but like me now in retirement. Bought second hand in 1997 the only repairs have been one hydraulic hose and new uj's in the 4WD axle, a starter motor and a few gallons of oil. Nobody mentioned green ones as mine is lime green.
Always put 32 hydraulic oil in the hydraulics and ATF in the torque converter.
Only ever seen lime green down this way, i always thought the 4000 was the skid unit