Well I could be wrong but I don't think that is the HO motor. If it isn't then it would be more work than it was worth unless you changed it all over with the roller cam and the firing order. I know there is more to it than that but can't remember at the moment.
For a v8 conversion, it is doable. You need to verify the firing order. You can plug the injectors in to match the firing order (might have to lengthen wires). You will not have the HP of a stock 5.0 HO. IMO if you are going to do a v8 conversion, give it some balls. 351,393 or 408, 460, 514 something like that. To me, it is not worth it when I could just go out and buy a stock car with 5.0 HO.
If you just want a v8 to put in, yes, it's the same physical dimensions as the ho block. you would need a mustang v8 harness as the location of the ECU is different. You would need a Mustang tranny as the tailshaft length is different. You would also need the crown vic ECU to run it. Also all the sensors for the engine and tranny from the vic. Other than that... piece of cake!
Oh, and my son reminded me that the power brake booster has to be replaced also because the 4cyl booster is too large in diameter to clear the valve cover on the 5.0.
the only other ford cars that had the ho motor besides the mustang where the lincoln lsc i just saw one at the bone yard that i bought my turbocoupe rear end from guy wants to sell it for 150 and it runs