Spin and shake will screw up ALL automatics. Every T/D and T/S guy I know has a spare glide or 400 or Lenco. Most Powerglide users I know have at least two others laying around. Buddy of mine running Super E back in the 90's went through at least two glides every race! Built right, used and maintained correctly, a 727 should handle any of our 6-900hp engines. I do have a picture of my buddy's '63 Belvedere that looks like it ran over a deer on the starting line. CSR shield barely dented the floor. There wasn't a piece bigger than your fist left. I'll try to find it and post it.