Do the OEM "running boards" fit a 2003 4.6L?

[ncx]

Forget the 3.0/4.4 stuff, that does not apply to you. The only thing you need to know is:

1. You will not use the arches that come with the running board kit, they work on the 3.0/4.4 only, not 4.6/4.8. You will have these parts leftover, unused.

2. You will need to buy the correct rear arches, part numbers in the thread I supplied. Front arches are totally optional, not required, it's up to you if you want them.

That is it. Order the right flares for your 4.6, order the running board kit, get the rivet gun and a few extra rivets and you are good to go!

ps... the polyurethane flares you linked to from the catalog are hideous, IMO.