I have achieved an impressive 373,000 miles out of the engine with no rebuilding. (1996 Ford Explorer Eddie Bower 4x4, 4.0 OHV) of course the accessories are another thing. 4 Alternators, 2 water pumps 4 radiators, 1 radiator fan, 1 fuel pump, 1 front driveshaft, Ujoint set for front and back, new bearings for rear axle, 2 times of rebuilding the transmission (4R55E), 1 time of purchasing a re manufactured transmission. 1 Rear Ring and Pinion Set, All body bushings swapped to Polyurethane around 180K miles, 2 rebuilds of the transfer care (Case half stretch on the horrible borgwarner, right now I have the range hub gear piece welded on the shaft so it stays in permanent High Range mode). But Alas it could not get to the 400K mark. I recently had the head gasket start a very slow leak, coupled with the coilpack starting to die, I decided it was time to retire her. So I picked up a Tahoe instead. But now that the Explorer is no longer my day to day driver I have pulled the engine and tranny out right now. I am doing a full and complete teardown and rebuild so that I can convert my Exploader into a full time offroad vehicle. I still say the Engines are the best pieces on the Fords. The 4.0 automatic transmissions are horrible pieces of garbage that die quickly at towing applications, the transfer case always seems to buldge. But the 4.0 pushrod did its hardwork. lol
~jon