Need a little help with a 4wd diagnoses. I purchased a used 1989 Wrangler and no prior info (towing yard lien sale). When jeep placed into 4 WD it gets wheel hop when going straight, like you are making a hard turn on hard dry surface. Rear end is a Dana 35c but perches appear to be about 1” farther apart then the springs when springs suspended without the carrier attached. Appears to have been changed. It appears that the gears in front may be stock 4.11 and the rear something different. Any help on identify if the rear end was changed would be appreciated. There is not a ratio tag on the rear differential. Did some Dana 35c jeep differential have different spring perch widths? Thanks, this jeep 4wd stuff is new to me.