Do you have a commute? Do you care about gas mileage? Is your exhaust very loud? If you drive alot of highway miles i would suggest the 3.73's, even if you dont if you're planning on upping the horsepower the 4.10's might be a bit short for you're liking, especialy for the highway. Either way, my vote goes for the 3.73's. Crusing on the highway with 4.10's = high RPM's = increased engine wear = bad all around.
2002 Mustang GT - Black, Red Stripes
Mods: CAI, UD Pullies, Hood scoop into heat extractor.
'01 CBR F4i 600 - Black/Silver
Mods: Chromed Wheels, Hindle Exhaust, Rear Fender Eliminator, K&N Air Filter.