Running 10.60 at 126 mph car seemed to be trapping at about 6500 with 3.91 gears . So when I built the Dana with big plans of spraying it I didnt want it to be trapping over 7000 so I decided to go with the 3.73 since there isnt a lot of gear options for the Dana. I thought if I can get it to run 10.00 with the 3.73 it would be getting right up around that 7000 range.