Does anyone know what parameter would be letting the TCC lock at 74MPH while at W.O.T?
I've just been doing some W.O.T test runs in my van and noticed that the TCC is locking on once I reach 74MPH and stays locked until I lift off.

It's a 1993 4L60E running an $OD bin, 8625 PCM in a modified G20 van.