A GM 6.0 will make more bottom-end torque, the 5.3 will need to get up in the powerband before making good power. This was evident in my TJ that had 40" tires and a stock 5.3... even with a 4.3 Atlas and 5.13 gears, it didn't have tire-spinning bottom end that I had hoped.Still pretty torn on engine setup, I am convinced on a 5.3 for about five minutes then go back to a 6.0 until I see the price. Any advice on that front?
The price difference is a big factor, IMO a 5.3 with flat top pistons and an aftermarket cam would have more power, but still not 6.0 bottom end. HTH!