4L80E is suppose to be a really stout tranny, and it is the conversion that a lot of people are going.
however, it is also an expensive route to go. the tranny isn't cheap, and then it has to be computer controlled.
you can get
the raptor which is a 700r4 that allows towing in OD, and also is guarenteed up to 600 HP for around $1500. an expensive 700r4, but when you consider what this tranny will handle I think it is a pretty cheap option.
