Aftermarket gears?

You should add a clutch tamer. Post 15 is right on the money. If your clutch is setup right and your gearbox is built to stock with stock part you should be able to throw 6-700 HP at it and the stuff that brakes is from the slip yolk back IE u-joints, diff, axels, then those parts should be upgraded. Not the gear stack in the gearbox.