how tough is a A518

Good stout transmissions.
These Mopar OD transmissions are made and used mostly for vans and trucks and when you put one in a classic car you have to feel pretty comfortable about it handling it.
In the trucks the trans is tow rated for thousands of pounds more than my car will ever need by itself and the car is a thousand or two less pounds than some of the trucks they were in.
how much h.p. will they handle ?