Originally Posted by USAFBowman
The mounting set up is completely different. Only way I think you could possibly do it is if you got a header panel (headlight mount) from a 99-04 and install that in your truck if they would fit.
When you go the other way, 05-07 lights in a 99-04, you end up having to cut a portion of the core support/header panel whatever you want to call it. Therefore, I agree that if you really wanted 99-04 lights, that panel would be needed.
I have found 05-07 lights on eBay for $150-ish. Personally, I would pay the extra money for the cleaner 05-07 look.