The ratio, in your example, 3.73, means that for every 3.73 turns of the driveshaft, your tires will turn once. Stock gears are usually 3.27, some are 2.73, and 3.08 though. The lower the number, the higher the top speed, and fuel mileage to a certain point. The higher the number, the lower the potential top speed, lower the mileage, the quicker you can accelerate.
Stock gear's are spec'd for super long engine life, and gas mileage, as well as noise. So they aren't optimal for a performance standpoint.
Usual swap's on a mod motor car like your's are 3.73's, 3.90's, 4.10's, and 4.30's. Do you have an auto, or five speed? how far do you drive everyday? On the freeway? Going to go drag racing? Gear choice depends on alot of thing's.