Are all 4.8's created equal
 

as far as rotating assembly's go are they all the same strength wise, if not what years are the best? when did the rods change?

In a boosted application is the 4.8 better, worse, or equal to a 5.3? redline around 6500rpm

you should check out the lasted hot rod magazine article about the boosted 5.3 that ended up being a 4.8. Made over 1000hp on the stock bottom end. only thing they did was open up the ring gap to keep them from "butting" at high boost levels.

What he said. 1200 hp from a junk yard 4.8 with twin turbos.