Oldgreen51,
I kind of like the clutch head screws and bolts, after completely disassembling and reassembling an entire truck ('50 COE). I much prefer them over slotted or phillips heads. To work with these fasteners you need the proper drivers or bits and before you attempt to mess with an old clutch head fastener, you need to clean out the hole. The sides of the hour-glass shaped hole are straight, so to get the driver in there all the way, you need to clean it out with a sharp awl or other tool. Get all that rust, grease and dirt out first. If done properly, you will either remove the fastener or snap the head off the fastener, before it slips out. What more could you ask?
If originality is not important then use whatever is handy. I would go with a torx, square hole or other straight sided fastener before I would use a slotted head screw or bolt. I was trying to retain an original appearance to my truck so I bead blasted and reused all the fasteners that were not damaged upon removal.
Sometimes the hole was already buggered up by someone else and the driver would turn in the hole. The metal would be lifted up around the hole, and occassionly I could save a fastener by using a hardened punch to tap and flatten the metal back down into place. This would be enough so that the driver would have something to grab onto and turn. This worked on applications where alot of torque was not required. If damaged alot it is best to find a replacement screw or bolt.
Kent
