Aftermarket gears?
i have a tiny motor in comparison 320 ftlb max
so i got rid of the six cylinder based stuff
i went with a 10 inch organic plate over the orginal 9.5 size, and a clutch cover off a modern 5- 6 liter fuel injected v8 (GM holden)
so for my 300 ftlb i have a modern car clutch designed for 400-500
standard parts both, from a "Big Boy's" motor rather than a 6, on a custom vented lightweight steel flywheel.
i.e I went with the premise of "Good Enough" rather than race clutch.
i'm running an Australian 4 speed single rail box (like a mini ford SROD with sensible gears) on the opposite side of the world (uk). no parts made since 1980, has to stay in 1 piece...
setting my clutch bite point higher, let me soft launch better and i ran a PB doing that.
i.e i started moving earlier and did not drag the motor rpm off the torque peak in the process.. hence better 1/4 mile. clutch slip for a very short period of time helps....
instantaneous torque seen by the gears is reduced, but with some slip the torque that is continually supplied to the rear is more likely to turn the wheels under traction than spin them. its a "cushion" to cater for your sticky tyres... the clutch operates more like a torque converter, for milliseconds until it locks.
Dave