We pulled a 25' TT with a 2005 Tahoe with the 5.3. It's a capable motor and vehicle but I didn't like 3,500 - 4,000 RPM on hills just to maintain 50 or 55 MPH. With any 1/2 ton vehicle, you will run out of payload (for tongue weight) before you run out of towing capacity. Do your homework with loaded trailer and tongue weights, weigh the Tahoe with full fuel, occupants and gear, and do the math from there.
Rob