the 4% calc. is assuming 245/50r16's out back. (my situation) which are 25.7", which is 0.1" smaller than 225/55r16's according to bfgoodrich's site info. for me it was not worth the hassel (not real mecanically inclined) of swapping out the tranny gear for the 4%. Never took the time to figure it out, but I'm betting the 7 tooth tranny with the 21 tooth speedo is not much closer than 4% given the diff. in tire sizes.
there is a formula in the FoMoCo wish book to figure all this stuff out. I can post it when i get home.
Bye for now...
|