Emission Systems For Cars And Trucks Cheapest Parts On the Web

ok here is the deal, im goin to buy a kit for 67 or 68 mustang coupe which includes the following
One Upper Nose
>One Lower Bumper Cover
>Front Eleanor Hood NEW WITH LOUVERS ON THE SIDE OF SCOOP
>One Trunk Lid Fastback or Convertible/Coupe
>Right and Left End Caps Fastback or Convertible/Coupe
>Set of Four Fender Flairs
>Right and Left Upper and Lower Side Scoops, for a Convertible/Coupe you only get one Lower Right and Left pair of Scoops
>Right and Left Side Pipe Covers
>One Tail Light Panel
does this kit mean that i can take out the original hood off the car, and put the one from the kit? or its gona go onto it?
basically i wanna kno if the kit is gona replace the original parts or go over them?
thank u