There are various models of NV4500; the shifter base can only be changed on later years with the "square top" lid (1995+ for GM, 1998+ for Dodge) where the shifter base is removable. The early years had an integral shifter tower; however a later lid can be fitted to the early trans.
Note for GM models of NV4500 there are two different lids - lid casting # 25137 for 1995-2000 and lid casting # 33893 for 2001-2007. The base mount for this later lid is 1/4" higher than earlier lid, requiring a deeper stub - i.e. each model requires a different shifter base.If you install the wrong one, it will either bind and jam or could lead to premature wear and internal transmission damage.
As the lids are interchangeable, there is a risk of mixed parts on any rebuilt unit regardless of application - so best to check the lid casting number (near front center of lid) when buying a shifter for any NV4500. If you have an aftermarket lid with no numbers, it is almost certainly the shorter lid used by Dodge & early GM. Depth from flange face on lid (w/ base gasket removed) to bottom of notch in rails would be ~ 1.75" for Dodge & early GM; 2.00" for late GM.