Are you swapping the 99 5.0 into a 2002 or 2001, cause your info says your Sport Trac is a 2001. Pats E disables the starter in the PCM, Pin 28 circuit 325 DB/OG acts as a ground for the starter with Pats E, without the correct key, the engine will not crank over, which is why with a 5.0 swap that wire must be removed and grounded for the starter to work properly.
You installed the 99 5.0 and 99 PCM, what wiring have you done so far? The 97 PCM does not have Pats but also the fuel system is different than that of the 99 as well, the 99 is a returnless fuel setup and 97 is the return style. There will be some pins on the C110 and C139 connector both that need to be changed.
Still if the wiring is all done correctly the engine should at least crank over but will not run as long as Pats is an issue. You will need the Pats transceiver and module with wiring from the 99 Explorer, or you will have to disable Pats in the PCM tune.
I can help you with the wiring, but I am not sure if the 97 PCM will work well with the 99 5.0 setup, it would be easier to just disable Pats in the 99 PCM if you can.