I bought a cheap "impact screwdriver" used a common head which would fit snuggly, couple whack with mallet and presto.

Point: Those Impact screwdrivers are really great for turning rusty stuck screws, including cluth head if its a tight fit.

I'm slow, but consistent........consistently slow!

Loy, 1950 Chevy 3600 3/4-Ton

http://s522.photobucket.com/user/Shellology/library/1950%20Chevy%20Truck?sort=3&page=1