[MKS427]

The parts will be about 5-600. Dederichs Motorsports 682 365-5555 is a Tremec dealer and can get the parts you need. If you carry the trans into a shop, you are probably around 4-500.
Did you consider a rear gear swap?
I run the wide ratio with a 3.08 and short tires (25.43") and I can cruise as low as 50 mph @ 1350 rpm. However, the motor is built for a lot of torque. I did have to switch to EFI from a carb to get it to work below 1700 rpm.
Hope this helps,
Mark