Wrong again... The 2765 clutch is a touch shorter since it doesn't have the HD fins in front. Granted, this clutch isn't designed for the heavier steel fan blade, though many use it them with it with no problems.
You oughta do a search on bigblockdart.com. There are plenty of folks running fan clutches on BB A-bodies with radiators in the stock location- several of whom are on this site too.
To the OP- don't be afraid of .250"-.375" of radiator-clutch clearance. Just run some sort of motor forward/aft limiter or a thru bolt thru the DS motor mount and you'll be fine.
