Need Help 6.0L swap!!!

I have a 2001 Chevy silverado 1500 and it has the 5.3 with 170,000 miles on it and I am looking to replace the motor. I want something with some performance and I want to replace it with a 6.0L and have tuning done on it. I need help on deciding on what would be best for my situation. I daily drive this truck and wish to continue and still get decent gas mileage. Does anyone have any suggestions as to what block to use, Lq4 or Lq9, what heads to use and what cam to run. I am planning on having the tranny beefed up a bit to handle it. I am just having a hard time figuring out what set-up to run to make it run good and have some balls but still be dependable. Any input would be nice

Stay with the 5.3 if you want gas mileage.The 6.0 is a gas hog.Plus the transmissions are differant too,the 4L80E is behind the 6.0.

Yeah I agree. If you are even considering your gas mileage stay away from the 6.0 It will stuck your tank dry in the blink of an eye.

I agree the newer 5.3's have more balls. That and the price you will save on the 5.3 you can tune your truck to be no doubt better than the 6.0