Yeah, if power is what you are after there are other ways to get it.
Stock for stock the 4.6 has a better power/weight ratio than the 5.0, but the 5.0 has better aftermarket support.
The problem with building power out of a 4.6 without a blower is that it is already an interference engine, which limits you on increasing valve lift/duration. A 5.0 can take a 500-lift cam with no problem.
As 85 said the 4.6 is a wide bugger, and a tight fit in the bigger vehicles it was in stock, but it has been done into a Ranger.
If I was looking for sporty/zippy/power and I was considering doing something as work intensive as a 4.6 I'd look into one of the new Coyote 5.0s, or an Ecoboost anything. The 2.3L would likely fit nicely and easily, as it is more or less the same block used in the later 2.3 Rangers. The intake and exhaust routing would be the worst of it. The high-pressure fuel system is self contained on the engine. Mechanical fuel pump fed 35 PSI from the tank pump is driven by the cam and steps the fuel pressure up to the 1500+ PSI needed for direct injection, so you basically just need to hook up the one line for fuel. I think wiring would be the worst part of that job.