If you are towing more than 2,000 pounds without trailer brakes you are endangering everyone else on the road not just you. I had an 07 Trailblazer with 3.42 gears and the 5.3. The 4 speed transmission was a liability not an asset. It would upshift too soon and not downshift when it should. That engine, like most modern V8s, require higher RPMs to make their power.
The vehicle was very comfortable but the reliability sucked. It had electrical problems, stabilitrack problems, and many other issues. I bought it certified in 2010 and just sold it this year. If I remember right the tow capacity was about 6,100 pounds and would have been 6,600 if Iit had the 3.73 gears.
Towing a 5,000 pound boat shouldn’t be an issue but get some brakes on the trailer.
