BigBamaBoy65

Hey guys. This is Nick from central Alabama. I've read several threads here, but this is my first post. Anyways, I have a 2000 3/4 ton 4wd 6.0L LQ4 with the iron block/heads. The truck is in good shape with only 168k miles, but the transmission needed an overhaul. Long story short, one thing snowballed into another and I got talked into tearing it apart and painting the frame, front suspension, rear end, and spraying bed liner in the box. Me and my dad built the 4L80E and freshened up the transfer case. While we had the motor out we decided to go through it to and freshen it up also. The truck will be driven daily and tow on occasion. The previous owner ran it a little warm a few times, and it has the LS cold knock. That's the main reason for the rebuild.
This is our first LS build and I wanted some opinions on upgrades. Keep in mind I don't want to hurt the 14 mpg any worse than it is already.
With that said I have looked at dropping flat tops in, a small cam like the vinci 112 grind "butt kicker", 1 3/4 long tube headers, cat delete, down stream 02 delete, a tune (advise on what octane?), chromolly push rods, valve springs, double roller timing kit, whatever else y'all think I'm missing.
I already have the K&N CAI, a complete gasket kit, chromolly ARP exhaust manifold bolts, MSD wires and Delco plugs.
The truck will be lifted 7" with 35" Toyo's and 4.56 gears.

Sorry for the long post haha.

Thanks,
Nick