Can you be more specific about what cross member fab and how much is required to fit the 200-4R?
Keisler uses the 4L60E which is a derivative of the 700-R4, so I was looking at possibly using the 700-R4 instead. It has an anoying round module in the way of the crossmember though. (see attached picture)Might require moving the motor & trans forward a little to clear it.