C-4 in Project Con-Vert has Pa C-4 with MVB and a t-brake. Its the only way Ill run a automatic (MVB) on the street in performance application.
As far as line pressure being too high CAN/WILL contribute to failure. The 200r4 that are in the GN's a same way, but dont think its from the valvebody. Im not a tranny guy but I sure have been through an ass load of them (GN).

Ive HEARD the same thing about running 4.10's /AOD on the street. They dont like the pressure.
Do you know Toby Gant?? He is local to Tampa and KNOWS the AOD's