I installed one on my 08 and had to use the pieces you bought. It really wasnt all that easy installing. I had to buy a few extra parts to make it fit right, but they didn't cost more than 5 bucks. I had the most trouble installing the brackets, they didn't fit very well. Also, make sure you tighten the crap out of the bracket attaching to the throttle body. It loosens way to easily.

 

i still have my stock airbox, i dont know what to do with it i fig id keep it a while and if anything put it back on when i get another truck, but i dont see that happening for a while