They do not have a part # on them. Just a letter stamped into plate. it will be under manual valve and if it is TR will be an X . The GM parts ones have the X on a tab next to the 1-2 accumulator.
And just for info, all plates are the same with the exception of early and late (84 and later is late) and hole diameter for apply.
ANY PLATE can be very very easily made to performance standards.