the stock rear gears are 3.90:1, for just gaining 0.17, the 3.73:1 you suggest would likely not make a noticeable improvement - there are
3.38:1 gears available [scroll down about half way] to install in the stock rear, they were a 'mileage minder' option originally - it's more expensive, but requires no change in rear end mounting, e-brake setup or driveshaft - I don't know if any later rear with as good a ratio could be just bolted in, otherwise folks use car rears with 5 bolt patterns for ratios in the low 3's
Bill
