I havent dug into clutch stuff yet but are you sure he put the right plate and disk in? They dont have the right disks anymore from what I have heard. You have to have the old one resurfaced because the springs are on the wrong side and it makes it too big or somesuch.
I know that doesn't help much, but maybe someone with knowledge of the borg-warner clutch disks (discs?) will reply and clear it up some. It has something to do with the diaphrams.