While trying to figure out a T-case shifter bracket from my 4L80 to T-case I'm now questioning how the H-N-L operates. I see if you do a twin stick you need a different 2h-4h shift rod but wondering why? How does it affect the H-N-L shift lever? I can move the H_N_L lever no matter what position the 2wd-4wd lever is in?