1993 F350 7.5 4x4

Original owner plugged trans cooler on radiator and ran a small external front mount cooler. I just added a larger trans cooler and new radiator.
Which line is In and Out on the trans?
Is the proper order: Out trans> top of radiator >bottom of radiator > top trans cooler > bottom of trans cooler> back to trans. ?

Adding new gauges as well.
Where is the oil pressure sending unit? Going to remove and run gauge from there.

The coolant temp sensor is the one next to the thermostat housing, correct?

Thank you for your time.

 

The oil pressure sending unit is behind the manifold, directly in center of the engine block.

Attachment 293566

 

If that's an E4OD the line towards the front is the pressure side and the one that goes to the rear is the return.
I'd plumb the coolers the way you mentioned, radiator 1st, top to bottom and then the aux cooler.