Please don't, they will either work or not, just let us know in here thanks.
Actually, what you could both try if this isn't your set up, have no other modules on your bench set up, the Allison is using 29bit CAN where the ECM's are 'normal' , it might be that with two modules on the bus talking different CAN protocols over that hour something gets messed up. You need to put a CAN load on the TCM if it is the only thing connected (120 Ohm resistor over CAN H and CAN L).