Thrust bearing problems on big block chev

I have suddenly started damaging my thrust bearing on my 454 big block chev after 4 years of racing and 168 runs . It is a 750 HP NA 469 cui big block with a power glide trans . It runs 9.1s at 149 mph at 2825 lb . I managed to catch it before damaging the crank so I just polished the thrust while still in the engine and replaced the bearings , ran it on the Dyno and everything was good . Ran and won the next meeting and damaged it again . Again I caught it in time so went through the process again but this time I lowered the cooler line pressure from 150psi to 95psi by using a bypass pill back to the trans pan . The pressures were measured while on the trans brake . Raced the car again and did well but damaged the thrust again . What could have happened after 4 good seasons of racing ? Can anyone help?

 

Wrong area.

 

Crank bent

 

Torque Converter hub pushing in on the crank ?? Maybe was setup for thicker mid-plate ??