I have a 2008 Avalanche Z71 which I love. I recently purchased a camper with a dry weight of 4800 pounds. I pulled the trailer home and felt the engine was undersized. I had the truck in trailer mode. The truck kept shifting gears on the slightest inclines.
I would like to exchange the 5.3L for a 6.0L engine. Has anyone ever done this before? The blocks are the same and I would use the computer from the 6.0L.
The 5.3L has no issues as far as engine light and purrs like a kitten. I have never gotten above 14.7 mpg on a trip and that is by using automatic speed control or just babying it.

 

It would just be cheaper and easier to throw a cam , converter,and tune in it. That will get you pretty much where a stock 6.0 would put to the tires anyways. If not a little more. Look and the btr truck norris cam. It's the biggest they make to retain your stock converter. Oh and buy a range dod disable off of amazon. It will save your engine.

 

I'd be more concerned about the rear diffy They don't like pulling heavy stuff. My brother was pulling a 26 ft camper across South Dakota a few years ago. Blew the rear diffy out in the middle of nowhere. Cost him $5K to get it fixed.

 

going to look into the cam. Thank you.