NBS 4x4 LS6 swap mpg question

[pl4yboy]

Hey guys, my frist post here, and i have a quick question.
I have a 5.3 iron block out of my fathers 2002 tahoe, he swapped it with an lq4, and the 5.3 is at the engine shop being bored over to a 5.7. I have a complete LS6 rotating assembly, im getting a pair of 243 or 799 heads, and a stock LS6 camshaft.
This is going into my 2006 Silvy with 3.73 gears,, 4l60e, stock tires, and 4x4 push button regular cab short bed.
What do you think my mpg would be?

Depends how you drive. It's that simple. I get 18-20 in my crew cab z71 6.2. I got 19-21 in my RCSB z71 with the 5.3. My RCSB 4.8 4x4 got 15 no matter how it was driven.