DISCLAIMER: For those of you list members who, like my little cousin's Barbie, hate math - you may wish to stop reading now...

Anyway, all other things being equal, the difference between 3.27 gears and 3.45 gears is approximately 5.3% (3.45 - 3.27 = .18 differential , 3.45 * .053 = .18285). This amounts to a theoretical torque increase of 5.3% at the rear wheels, which can, under certain circumstances be beneficial.

However, please keep in mind that one must take into consideration how much time the car will remain in its torque band throughout the quarter mile run. This is easily calculated by knowing the gear ratios in the transmission (2.74, 1.57, 1.00, .67 OD on 200-R4 transmission), rear end ratio, tire diameter and width.

Assuming you still have the stock cam, heads, torque convertor etc.. you can INFER the torque and horsepower band of your vehicle through its ET, weight, trap speed, and final rpm through the traps quite effectively. Please keep in mind that by switching your gears out to 3.45's you might just have to have another "drop" out of your motors torque band by shifting into a pretty stiff OD 4th gear. With the stock convertor, you may just SLOW down unless you optimize other facets in your combination to take advantage of the decrease in apparent load to the motor. This is because your motor, being out of its torque peak for one more cycle (another gear change), is slowed down momentarily as it gets back into its effective window of performance. This is why a lower rear end ratio (higher numerically) can potentially slow you down in spite of having a bit more "thrust" going to the rear wheels.

If you have the gears sitting around and are handy with adjusting backlash and testing ring gear print under load and no load conditions w/lithium grease, great.. Otherwise, you may wish to use the resources ($$$) to improve your vehicles performance through a more cost effective approach IMO.

If you like to play with mathematics like I do (sheltered life..), which is cheaper than pulling your axles and carrier to swap gears in your vehicle, you may wish to experiment with the following formula. It can be optimized a bit better through Calculus, but this way it is simpler and even Barbie can use it...

Once you have figured out your torque band and approx HP levels through trap speed, vehicle weight, etc.. Use this theorem to establish a torque baseline. You can figure out how much tire to use, gear changes, thresholds of adhesion, engine modifications, etc.. by plugging and playing with the formula:

T = engine torque in ft/lbs to break tires free (spin)

W = weight on drive axles

F = coefficient of friction between tires and road surface (this will obviously vary w/tire type, slick, durometer hardness, temperature, etc..), I use .7 for the tires I use (48 durometer at 70 degrees, 9 inch radial, 26" diameter)

R = Rolling radius (should be measured w/driver in car to decrease deflectional difference in radius, this is especially critical if driver is gravitationally challenged)

G = Rear end ratio

Y = Transmission 1st gear ratio

12= conversion to foot/lbs

Assumptions: 100% efficient transmission (not possible), "little" transfer of weight on launch (possible, but not likely on a well setup chassis), no deflection (wrinkling) of tires on launch to upset "R" value.

This formula has been simplified considerably by the use of certain assumptions. These assumptions are extraneous variables that will upset the final validity of your results. However, it is accurate enough in its present state for some utility. If you need help plugging in numbers or would like a better (and considerably more complicated) version of this formula, please e-mail me, I'm always looking for an excuse to get away from homework..