I suspect what is happening is one of the valves in the valve body are stuck and as soon as you put it in drive, the manual valve directs hydraulic fluid to what is supposed to be first gear and it sends to the incorrect location and it stalls the engine. Most likely it is applying the torque converter and this will immediately stall the engine.
I suspect you have codes in the system. If you are able to get those pulled we can confirm this or they will point us in a better direction but that is exactly what it sounds like to me. These 41 or 62TE transmissions have been known to do this so it is not the first time I have heard of it.
Let me know if you can get the codes and we can go from there.
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Monday, May 13th, 2019 AT 6:20 PM