Originally Posted by
Epstein
The step down at the edge is to increase the preload the pressure plate. It's really up to your pressure plate manufacturers recommendation whether the flywheel should be stepped or not. If you need one and don't have it, the clamping force is reduced. If you have one and don't need it, the TOB and lever might be in the wrong position. I've never seen one like that, but then again I don't play with aftermarket KA stuff. The SR stuff is flat.
I was going to say something similar, as far as the manufacturer deal, plenty of stuff is interchangable, and virtually all stock stuff, doesnt have a step like that, I highly doubt if ACT, spec, CM, etc have a plate that will fit the ka flywheel, and something else, that they're going to make a specific ka one just to require an extra step in resurfacing when it comes to the flywheel.