i have been doing some research on what diameter the stock clutch disc is on a 1992 z28, with a world class t-5. i dont know if it is either 10.4 inches or 10.5 inches, or if it even matters. are there benefits with chosing one or the other. thanks for readin and helpin out. also on a scale from 1-10, 1 being an oil change, and 10 being a transmission overhaul... what is the difficulty level on replacing the clutch myself assuming i have every tool... and how do i know if the flywheel needs replacement/machining/etc. thanks again.