Thanks for the replies, indeed it is an 8-3/4" rear. I have 3 third members, one is a cone-type posi the other two are open diffs. Between the three I have 2 usable sets of gears, a 2.76 set and a 3.91 set - with a 3 speed 904 I am leaning towards the 2.76s for the street but am temped to throw...