I'm sure it's been covered before, and I didn't want to make a new thread but I couldn't get an answer in the cam thread.

I'm getting most of the valvetrain from an '03 Z06 for free.
-springs
-retainers
-seats
-timing chain
-cam
-pushrods

Question is how much of this should I use on my '03 5.3L? The Z06 pushrods are still 7.400" but do you guys recommend getting hardened rods that are 7.425" to take complete advantage of this cam?

Things for sure are the yellow springs and cam, but the other stuff I was curious about. Timing chain necessary?

-John