Comparing a transmission/gear manufacturer's torque rating to your engine dyno torque numbers won't tell you much. When you are actually going down the track, much faster engine acceleration and pulldown rates come into play which can have a huge effect on the input shaft torque numbers. Turns out it's actually the clutch that has the final say as to whether the typical street/strip manual transmission lives or dies, as the clutch controls the intensity of the inertia discharge spike that is created as engine rpm gets pulled down against WOT.

To illustrate the point, here's some dragstrip data...



Here's some averaged input shaft torque calculations for the above graph. It shows this example's 425ftlb engine only produces 204ftlbs at it's 1st gear engine acceleration rate, but when that same engine gets pulled down quickly against WOT by the clutch, the input shaft see the engine's full 425ftlbs + another 1046ftlbs that comes from inertia energy exiting the engine's rotating assy after the 1/2 shift...



Here's those calculated input shaft torque numbers, multiplied by the transmission's gear ratios, then compared to this run's actual Accel G trace...



When you reduce clutch clamp pressure it reduces the clutch's inertia draw rate, which in-turn reduces the intensity of the inertia induced torque spikes sent to the transmission's input shaft. For this example clamp pressure was reduced enough to double the clutch's slip time, and that increased slip time cut the intensity of the torque spikes in half...



Those smaller torque spikes now last twice as long, which will also boost that area of the car's accel G trace.

Here's a graph comparing the slower inertia discharge rate and the previous driveshaft torque numbers...



Notice the nice stair-step effect the clamp pressure change had on the torque spikes as it works it's way thru the gears. You could stick a 400hp shot of n2o between each of those spikes and still not exceed the torque applied to the driveshaft during that dead hooked launch

Grant