You should call a tranny shop about those AT545. Get their opinion on your type of application.

I do know the torque convertor slips A LOT and creates a LOT of heat, under heavier loads = engine rpms says high and vehicle slows down and torque convertor just keep generating more and more heat due to slippage (under load).

Note: You better plan on plenty of "cooling" for your overall plan.

Call an Allison shop and just ask the shop foreman, if he recommends buying one or if he would own one. Their answer or "lack of answer" or "hesitation in giving an answer" might tell you something.