Speedo Recalibration Help
(RPM * Tire Dia) / (Diff Ration * Trans Ratio * 336) = MPH
My 81 had the Performance Axel – 2.87:
(2000 * 27.1) / (2.87 * 1 * 336) = 56.2 MPH
New Diff = 3.31
(2300 * 27.1) / (3.31 * 1 * 336) = 56.0 MPH
How many teeth do I need to go up? Any idea what was stock?
Thanks in advance.
Last edited by MN81C3; Sep 19, 2007 at 12:33 PM.



