Speedometer Cable

i'm about to change mine out too and saw that looks like i have the 2 piece cable. Figured i would have to change to a one piece. Mine (72 Demon) is also going to stock instrument gage and 727 tranny (has 1" nut connecting to the trans).

I am also confused which to get. I don't know if I need the 80" length vs the 62" from Classic Industries. Also worried that the threads may not match to the transmission. Here's what I am seeing:

ATP Automotive Y-819 ATP Speedometer Cables | Summit Racing

3592360 - 1968-76 Mopar A-Body / B-Body / E-Body 62

https://www.oreillyauto.com/detail/...040/1972/dodge/dart?q=speedometer+cable&pos=0
Which one to get?
When online listing are confusing I pull the OEM part and fully identify it and/or take it to a part store to match it up.