Bearing repacking is pretty spendy! I had mine done at 30,000 since I was doing a lot of offroading and water crossings. If you have your wheels submurged a lot in sandy/silty water I would highly recomend repacking every 30,000. However if you just drive the street 50,000 should be fine.
2001 Ironman Daily Driver... 3.5" suspension lift (OME912 springs and 1" spring spacer), ball joint flip, 1.5" front diff. drop, 33"x12.5 TrXus MT, 16x10 Eagle Alloy rims, Interceptor, PV muffler, K&N air filter, Alpine Supercharger, Bilstein shocks, and some trimming.
2000 Ironman Project LS-1 VX... very slow progress but someday....... ohhhhh someday......