64swb: Thread is righthand. Jack up truck on left and lay under engine. You have good access there. Use a "cape chisel". 1 or 2 wacks with a small or med hammer is all it takes. Strike stud in a counter/clockwise direction. Work it out, 1 or 2 turns and then you can grab with fingers. This will work on clutchhead screws also. First try using some liquid wrench or Wd40 to lube broken stud.
Think Chevy!
