Supercharger

Exhaust and a k&n box/filter may help a bit.

I got an 02 5.3 with tuner, exhaust and intake. None really made a huge difference except for the trans adjustments... It sounds like its doing a whole lot more though.  On my 7.3 Ford I did exhaust, intake, added an intercooler, aftermarket turbo and a TS flip chip and came close to doubling horsepower and torque while sacrificing very little on dependability.  I won't touch the 2011 5.3 they run fine out the box. Does the 08 4.8 have the 4L60E trans or the six speed auto?

In the 02, that is one thing I like about the Hypertech programmer. You can adjust shift points and firmness and helps to make up for the lack of gears. As far as the engine tuning options go, just makes it ping and detonate.. sounds like pennies shaken in and empty Coors can, even if you run 91.

I'm just rambling now, supercharge and plan on buying a trans out of warranty if ya wants power.

Thanks for all the info guys, I may try taller gears in the rear end first but I have contemplated trading it up for the 6.0 or even a diesel.  I'm just not looking forward to the extra gas expense.

Pulling with the 4.8 is not bad but it could be better, just wanted to see if anyone was running a programmer or mods that they liked.

Probably going to regear and was thinking of running a Banks exhaust and intake system to help it breath better.  The Hallett gets heavy on hills, especially spinning 33' tires with that motor so it takes me a bit longer to get to the water but it still get's there.

Unitrax Driveline, Gears and Differentials
714-630-4327
Talk to Devin King.

Bought several parts there for my Gear Vendors project on the Ford. They do good business.