how tough is a A518
My parents bought two new dodge trucks, one in 98, and one in 2001. Both were 5.9s with 46re transmissions. The 98 they got rid of before it had 30k on it, and the 2001's trans gave up at 49k miles in California. Truck had a 50k mile warranty and Chrysler refused to cover the trans, last brand new Dodge my parents bought.
That being said, with how many transmissions floating around I am going to be using the 46RE's little brother (42Re/rh) in my 65 Dart convertible project. If you have someone that knows these transmissions and can go through them, they can handle a lot.