15 easy. Even your current set up will last a long time on that. Or like said get a 05 up 5.3

My current motor is cammed, heads (799 unported), studs, springs. But the bottom end is stock. I'm not sure how long the bottom end (particularly the rods) will last.

there is only one way to find out :)

We have been running 16psi on my buddys 2007 5.3 for a few years now and its been abused some kinda bad. It has a isky 212 114 lsa cam and isky springs in it and thats it.

The tune is goin to be your limiting factor.

My tune is pretty safe at the moment, ~11.3 afr and ~14 deg of timing on 91 octane (assuming E10) at 9.5psi. Meth injection is planned for the future but not used at the moment for tuning.

What kind of power is he putting down?

have no idea..its in a 1998 RCSB chevy with a circle D 3200, 4L80E, 3.42s, 28" slick and it went 11.3@118 with a 1.7 60'

What makes the gen IV 5.3L stronger than a gen III? Just the rods?

What engine designation should I be looking for... LM7, LY5, ...? And how can I tell by looking at the motor from the outside?

My 5.3 made 837 rwhp on 16 # , i did ported 243's and boost cam . It came out a 06 yukon with 75k on the clock .

Kind of similar question, its 04.5 and newer correct? Looking at an 04, how do I tell if its an 04.5?