Tonneau Cover Question
An 07 most likely has a tailgate spoiler. Some tonneaus have a replacement for the spoiler and some go over it.
Correct answer.
06+ came with a spoiler type of tailgate cap that extends back 2-3" vs fitting flush with the top of the tailgate. If your tonneau from the 07 was designed to fit over that factory tailgate spoiler it will hang out too far on the 04 without it. You will have a pretty big gap underneath and it will look awful( i.e. will hang over the tailgate too far plus contoured to fit around the spoiler no longer there ).
Most tonneaus require you remove that spoiler tailgate cap and replace with a traditional flush cap. If the tonneau from your 07 is that style then it will fit the 04 fine.
Here is what I am talking about. I will show you using some older pictures of my truck( 08 )...
Spoiler Tailgate Cap( notice how far back it sticks out ):

Replacement Traditional Cap( fits tight to tailgate ):


Traditional Tonneau( notice how close to tailgate it sits - wouldn't work with spoiler ):
06+ came with a spoiler type of tailgate cap that extends back 2-3" vs fitting flush with the top of the tailgate. If your tonneau from the 07 was designed to fit over that factory tailgate spoiler it will hang out too far on the 04 without it. You will have a pretty big gap underneath and it will look awful( i.e. will hang over the tailgate too far plus contoured to fit around the spoiler no longer there ).
Most tonneaus require you remove that spoiler tailgate cap and replace with a traditional flush cap. If the tonneau from your 07 is that style then it will fit the 04 fine.
Here is what I am talking about. I will show you using some older pictures of my truck( 08 )...
Spoiler Tailgate Cap( notice how far back it sticks out ):

Replacement Traditional Cap( fits tight to tailgate ):


Traditional Tonneau( notice how close to tailgate it sits - wouldn't work with spoiler ):


