@CDW6212R
If it were me, I'd go with EEC-IV of early '90s vintage, surely use Mass Air, not Speed Density (existed in F-Series still, then). Your 97 PCM (EEC-V) is much more complex and difficult to work with than IV, IMO. It added CAN Bus, with Transmission codes, etc., and if you choose to include a CEL, it will be ON all the time, thus useless to you.
In my conversions, I used NO CATS, where I had to pass Emissions, Phoenix, the criteria was by Year only, so an EFI set-up passed easier than carburetted! Without Cats! Single O2s either side, about a foot from the manifold outlet, where they were easily accessible. Those babies measured 0.00% CO! To register the Ranchero, an A.H. inspector noted I was dumping the output of the Smog Pump directly to the atmosphere, required it be connected to the exhaust pipe, as in the Mustang the eng. came out of. I ran a pipe down there, he passed it w/o even looking. I did have working EGR on all conversions. Note that my '90 F-150 has it's Smog Dump right out to atmosphere, underhood! That's only when it's switched there instead of into the heads, while idling. imp