Depends on a few things.What engine he has,power,etc. With enough power he can get away with a 3:08 set of gears,or perhaps 3:42s.I am runnuing a 350 in my 55,with an OD 700R4 trans. and 3:90 gears. With the OD it works out just fine.It will run at freeway speeds and gets 20 MPG all day long.If I was using a standard shift,or perhaps a 350 or 400 Hydramatic. I would want a lot taller gear,around 3:08s.
