Mustang guys...need help

I have a friend who owns a manual 99 GT. He has a stock clutch and wants to replace it but he says there is a problem

apparently he says stangs came with two size flywheels, a smaller one and a larger one. he has the smaller one and the clutch is for the larger one. But there are also 6 bolt cranks and 8 bolt cranks and he doesnt know which one he has, and i guess that makes a difference

Any input on what crank he has?

well the clutch should be the same on both

if they are getting a new flywheel they need to figure out where the engine was built.

6 bolt = romeo

8 bolt = windsor

hope this helps