Most of the experienced posters are right, IMHO. As long as the throwout bearing is not riding on the clutch fingers, whatever style, it has enough clearance. I don't measure, just set it up to touch and then back off a little.

As far as clutch design goes, I associate Long style pressure plates with Ford. But Chrysler and GM have both been using Borg&Beck and diaphragm clutches for years and years. Neat thing about them is the bolt pattern is the same so they can interchange.
Another neat thing (mainly for trucks) is with an 11" clutch you can upgrade to a 12" disk just by buying the 12" clutch set, it's a bolt-on. This is for the 143 and more tooth flywheel.
The 12" Borg&Beck in my '64Dog is a McLeod, but there was also a rebuilt 12" B&B from an early '60s chevy truck that I was watching on ebay. Turns out the McLeod was just a few dollars more, so my pressure plate is now red rather than blue.

R.