I don't know about the junk yard, but you WILL have to cut and drill your fenders to put them on your YJ.
Front: Dana 30 4.10: Yukon Chrome-molly axles / Super Joints & Lock-Rite locker
Rear: Dana 35 4.10: Yukon Chrome-molly axles & Lock-Rite locker
C & C Fab Tube Fenders (giving these guys a plug because they treated me so well)
Home brew oil-pan/bell housing skid plate and gas tank skid plate.