its hard to find

[GasGuzzler]

The 5.3 to 6.2 swap is pretty hairy. The 6.2 has the benefit of a 6-speed auto that is not a direct swap either. For the cost of a used 6.2 with 6L80 and complete wiring harness and computer, I'd check into aftermarket block and crank combos for bigger inches as described above.

[chuyr]

then maybe i should just keep the 5.3 change for better heads n a cam n charge it im looking at gettin around 500 hp to the wheels i know it might be hard but thats my goal