For some reason I thought we were talking about a truck. no matter, if a car, then disregard the rearend choices. A 3.08 center section can be had for the 55-64 rearend fairly easily. Look at 59-64 for the 3.08.
3.36 and 3.55 are also easy to come by, but you'll want the overdrive then to run at those speeds comfortably.
