10 bolt....?

[68Formula]

Nice thing about the 8.5" 10bolt (besides the fact they are plenty strong) is they are lighter, have less parasitic loss, and you have a wider range of gear selection without worrying what carrier series you have or using spacers to compensate). So as long as you have a series 3 carrier (2.73 up) and not a series 2 carrier (2.41/2.56 gears), you should be in good shape.

http://www.chevyhiperformance.com/te...all/index.html