I got my FMS 3.73 gears off of E-bay for $75.00 new and installed them myself.
I would have been sick if I would have paid 500.00 since I went no faster with the lower gears.
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88 mustang gt convertible bored to 306 BBk equal length headers mac cold air fender kit 3.73 FMS gears cowl hood nitto drag radials ford racing clutch flow masters h-pipe 160* thermostat 16 degrees of timing electric fan off 94' t-bird jacobs electronics cap and wires. Edelbrock 1 1/2 inch drop springs.