patrickt Sorry pat, not on my own fleet of toys. I have broken about 4-5 discs with either schattering the hub in the center or breaking the springs in the hub housing. My FE motor has the smallest bolts for the PP in any of my stuff. I have repaired the disc once already.
IMO if you are shearing bolts, as you know there are only 3 ways I can think of doing this, ABUSE, abusey, AH CRAP ABUSE.
I don't know why your bolts are coming loose but I am running a higher torque than you, I will have to check the numbers but it's like 38-45 ft pounds with the red. I do run a tap through all the holes before installing the bolts. Maybe this makes a differents. I also torque down the pressure plate like a wheel being installed on a car with a star pattern of 180 degrees per bolt. I have stopped with the 5,000 rpm holeshots and blowing the hell out of my equipment. 30 years ago, race parts where cheap along with trannies, rearends and clutches. Today a junk center section of a Jag with an open carrier is $6-800 dollars. No parts but the center. I have been lucky at swap meets and picked up some parts cheap. Major Destructor has retired from his stupid ways.
Pat I have seen alot of breakage and with people who I help and want to listen, I tell all of them to OVER BUILD your car. Bests parts, fasteners, motors, tranny and rearends. If they can't afford them then wait 2 months, put it on plastic, but get the best stuff you can. Maybe this is why the bolts have not sheared. I am not worried, I have a Lakewood.
Rick L.