V8-5.2L,Automatic transmission

I have a 1996 Dodge Ram 1500 2W drive. Automatic 46re… There appears to be a check valve in the lower line that runs from the transmission to the radiator. I have been told that is no longer available. I have put a 1997 trans (46re) in the truck and want to know if that check valve is still to be used or removed from the line. I had it blow apart on me and I lost all the fluid. Should I remove the valve from the circuit?

My car has 155000 miles.
My car has an automatic transmission.