I have a 1982 300DT that really runs super. The one thing that bugs me, is the low diff. gear ratio. A mechanic said it was (I forgot the exact number) about 3:45 to 1. How many other differentals will fit; how high should I go? Now I am turning about 3100 @ 70 MPH. I think the car should handle 2300 @ 70 MPH. Anyone have any suggestions? Thanks, jim Peterson