Mercon V or Mercon??? 96 Winstar

I recently installed a trans cooler in line. The commercial tech at Advance Auto reccomended Mercon V with pint of Lucas trans oil. I'ved have been told on this forum not to use Mercon V on 96 Windstar. Anyone have any comments on this subject?? and what should be done?

Assuming that you have the original transmission in your vehicle use whatever your owner's manual and/or dipstick states.

It will be one or the other. I believe that 96's call for Mercon. But verify.

I checked the online owner's manual site and it looks like 96's require Mercon.