I'm not sure where you are getting your data from. This is a very common modification on NPI engines. Did you watch the video I linked? It takes you through it step by step. As mentioned, as long as you take your time and follow the directions it is pretty straight forward.I don’t see a lot of successful pi intake swaps on non pi intake heads. I’ve heard a lot about leaks, so I’m a bit worried. 5.0’s seems to have way more support than 4.6.
My car had the Ford recall NPI intake with aluminum crossover when I got it. Eventually the plastic coolant port under the aluminum cross over where the thermostat is went away and started leaking. I then installed a junkyard PI intake (make sure you check what you are getting, most of the Crown Vics had Dorman intakes on them). That lasted about 3 years before that heater hose nipple where yours is leaking broke. I now have a new Ford intake on there and it is fine. My only gripe with the swap the first time I did it was having to wait for the RTV to cure, but on this last round I used some Aisin AB1207B1 that sets up quickly, and by the time I was done putting the engine back together it was ready to go. I hear Permatex Right Stuff is also fast cure, but I've never used it.