[tekenaar]

No

So can the step in the flywheel be removed and the stock clutch disc and pressure plate used?

If you remove the step and try to use the stock clutch, you'll never be able to disengage the clutch (relieve enough pressure on the pressure plate to release the disk). That's also why it's so important to grind the flywheel step the same amount that you grind the flywheel clutch disk surface, else you'll end up with a constantly slipping clutch . . . even with a brand new disk!