you're just pulling the old engine and plopping the new one in there? what year did the other 3.8 come from? you have to make sure you have the engine balance in consideration and that you have a weighted flywheel/flexplate for the externally balanced earlier 3.8's and a neutral for the internally balanced ones.. other than that, just keep track of your sensors, wires and vacuum lines and you should be fine
2003 3.8L V6 4R70W
Windstar Upper Intake with cool-air intake, MAC LT headers, BBK O/R H-pipe, and flow 40s, SCT tuner, FRPP Alum. D/S, 3.73 gears, Auburn HP limited slip, and Team Z LCAs, Eibach sway bars.
Best 1/4 time: 15.036 @90.92mph, 2.148 60'