Hi again. Just put in some new rotoflex couplings and went out for a test drive and icecream. That went well. I stopped along the way to set my idle down a bit and when I took odd again something in the rear end went BAM... After towing it home and getting underneath it appears my differential blew up. You can spin the driveshaft but nothing is moving anywhere else..I have not torn it apart yet to determine the extent of failure but it sounded pretty nasty when it let loose. I have enough parts to build a new 3.89:1 rearend but I need a 3.27:1 for the street. Anyone out there have a spare or one you would trade?? Thanks. P.J.