4.6 or 5.0 which is better?

[CADreamin]

You also need to consider where you live. If it is an area with enhanced emissions testing, not only will you have to deal with the 5.0 swap and wiring everything correctly, you will need to research the emissions laws and jump through whatever hoops you have to in order to pass the visual and dyno testing.

In CA, for instance, the laws are pretty strict. I knew of some people who would take out their off-road h-pipe and put the stocker back in come smog test time, then swap again after the test. Obviously you're not going to do this with an entire engine assembly.

Just something else to consider. As Deuce said, if you really decide you want a 5.0 you might be better off just buying a year that came with a 5.0