I have a set of LS1 heads that came off of my Vette that a friend of mine said I should put them on my 07 Silverado 5.3 along with a LS6 cam and of course change out the springs as well and mill them .30 Would it be worth it? I know that the LS1 has a bigger chamber, but milling them should make it up.

 

If the Vette heads are 241s you'll lose power...even milling them to correct
compression. The 07 5.3 should have 243/799 castings which flow much
better as well as having a way better combustion chamber shape (flow and
quench-pop)