3.73 gear on 98 GT automatic,

[surfbeast]

The gears will give you beter acceleration from a stop. With 3:73's you will not really notice any change in gas milage and your RPM's will only increase by a bit. You will be able to spin the tires a bit easier but your wife probably won't know the difference. When you get the gears this is what you need,

Gears : FRPP with pinion nut and pinion bearing and crush collar

gear lube 2-3 quarts, and a bottle of "stink oil" wich is tracktion lock oil from ford for the posi trac unit. About $ 3.00.

A 23 tooth speedo gear to corect the speedo $ 10.00 or the $ 100.00 sped cal unit from Dallas Mustang to correct the speedo to within .2%

Also, have the mech check your inner axel bearings and races, mine needed replacing and a so-so mech would have missed it. That would have cause major damage if left unrepaired!Before my S/C I could actually chirp 2nd, something unheard of before gear swap.

Look around for a good gear installer: Mine charged $ 130.00 for gear change, bearing change and transmission oil change. It took the guy 2.5 hours total to do. Other places wanted $ 225.00 min to do the gears, what a rip off!

Good luck