LU or NLP Trans id help

[CalgaryGN]

I have a new to me transmission and converter. Recently I took out my stock trans and 911 converter, and swapped the other stuff in. The issue now is once I put the car in any gear the engine stalls as if the converter is locked. What I am thinking is that I have a NLU modified trans with a lock up converter. So today I took it all out again and noticed the trans has no check ball in the input shaft but still has the oring on it. Is this an indication of a NLU mod ? What else can I check to determine what I have. Ideally Id like to make it work with my 911 converter LU, as I know it is good. Thanks