3.73s Or 4.10s

I speak like an engineer or physicist sometimes so here's the bottom line up front: 3.73s may indeed be the way to go for you, but the information about 4.10s being harder on a clutch than 3.73s is nonsense. Actually, the opposite is true. Yet I still recommend that you don't base gear selection on this fact alone.

Discussion:
4.10s do multiply the torque at the rear wheels, but that torque multiplication only happens after the pinion gear touches the ring gear in the rear end. So for example, 300 ft-lbs (peak torque for a stock 5.0) is applied through the clutch through the input shaft and to the gear cluster in the transmission where it is multiplied by 1st gear by 3.35. That makes the torque at the output shaft 1005 ft-lbs minus any mechanical losses. At that point the output shaft, yoke, driveshaft, yoke, and pinion gear all feel the twist of 1005 ft-lbs. The ring gear multiplies it by 3.73 or 4.10. The sum of the torque to the axles, wheels, and tires will be 1005*4.1= 4030 ft-lbs minus drive train losses.

There are 4 common things in racing that are particularly hard on clutches:
1. The torque your engine makes may simply over power the friction and clamping force that clutch provides. This results in clutch slip.
2. Shock (brief but massive torque) to the drivetrain, which takes into account vehicle weight, engine torque, transfer of engine and drive train rotational inertia, tire sidewall flex, and traction all at once when you drop the clutch to launch hard, or when you power shift.
3. The driver purposefully slips the clutch. This puts less shock through the drive train, but it builds more heat in the disk and pressure plate because of the kinetic friction between the slipping clutch disk and the pressure plate. "Slipping the clutch" severely decreases clutch, pressure plate, and flywheel life. The heat and friction can, even in one event, kill a perfectly new clutch by damaging the friction surfaces badly enough.
4. The RPM of the input shaft spins too high, which results in mechanical damage or destruction of the clutch disk. This will only happen if you're in the wrong gear or if there is a defect in the clutch.

In fact, short (numerically high) gears allow you to launch just as hard with less engine torque. This means you can launch from lower RPM. Therefore, you can slip the clutch less, or dump the clutch without as much inertia in the rotating assembly. That actually turns out to be easier on your clutch.

Now, if you want to pick your gears based on what will get you the best 1/4 mile ET, then choose one that will put you through the top of your power band in 4th gear through the traps. What do you think you'll trap? I'd guess something like 100mph give or take. You'll also want to cross the traps at around 5500 RPM. You didn't mention your tire size, but I'll assume its in the realm of stock, say 225/55/16. With this 25.7" diameter tire and 4.10 gears, you'd go through the traps at 102 mph at 5500 RPM. You also have plenty of room to grow. 6000 RPM will take you through at 112 mph. The stock rev limiter at 6250 RPM will put you through at over 116mph.

At 70 mph, the difference is 2530 RPM with the 4.10s and only 2300 with the 3.73s.

Good luck with your decision.

Years ago, I built an excel 1/4 mile estimator that has a gear/tire/transmission calculator integrated and I've fired it back up for you! Hope it helps. It was actually nice to use it again and refine it with some newer skills.

275/50/15 with a T5 and 3.73s


275/60/15 with a T5 and 3.73s


275/50/15 with a T5 and 4.10s

275/60/15 with a T5 and 4.10s