[Mr 5 0]

As The Deuce commented, the 4.6 is a stronger engine, overall, but it doesn't have the low-end torque capabilities of the 5.0. Both engines are 12-second-capable N/A (with gears and some engine mods) but the 4.6 can be a bit more complicated to work on and performance parts are noticably more expensive. Since the 5.0 is out of production the 4.6 is the only game in town so I would enjoy what you have, buy some gears and engine goodies and stay in the game.