The 5.3l and 6.0l have been proven to get almost identical milage when setup the same. Most who have swapped out the 5.3's for 6.0's, haven't hardly seen a change in mpg. The big differences between a 2500hd with a 6.0l and your tahoe with a 5.3l is trans gearing, torque converter stall, rear end gears, and shift strategy. The 1500 tahoe is setup primarily for mpg, many had 3.42 gears, a low stall torque converter, a REALLY deep 1st gear with huge rpm drops between the shifts, and tuning setup to keep the rpm's down to furthur optimize milage. All 2500hd, 3500, and many 1500hd's with the 6.0l had 4.10 gears, they all had the 4l80e trans geared for optimal towing, a LOOSE converter to keep the rpm's up, tuning that is setup to hold the shifts out even driving easy, and the torque converter is basically on or off, not varied like the 1500's to keep rpm's down as much as possible at all times. Put a tune in your 5.3l, and it would be a completely different animal towing.

Done all my V towing with a GM 5.7. First in a 1994 GMC C1500 and presently with a 1992 Chevy C2500.

Thinking about switching over to a first gen tundra with the 4.7 I-Force.

For my V20 I used a v6 Rodeo and a v6 Explorer for 15 mile rides with no problems and plenty of pull.
I also used an OLD Ramcharger 318 that was a dog that couldn't move itself.
I would not want to use any of them for lots of long hauls on highways with hills.

My 05 V6 Explorer crapped a transmission last fall at 198K miles. Now I have a brand new Hyundai Elantra and have to borrow a truck to launch this spring. I haven't been truckless since the 80's.

I'm towing my V20 (150 OB, dual axle trailer) with a 2014 Ford Explorer (6 cyl XLT). It's been great. I launch 20-30 times a season.

Thanks for the replies. You all have given me something to think about. I also have a tandem axle trailer as well.

97 gmc sierra z71 with 250k. ive had her since 98 with zero major problems and have towed many boats and various trailers with her. in fact probably half of those miles have been pulling a load. at the ramp i put her in low and just let the 5.7 idle. even with the old heavy 23 chapparral walk around, no
throttle needed.

guess what im saying is your honda can suck it!!! and your little nissan too!!!! buy a real truck! MERICA!!!!!!

yall know im kidding, right? those little jap trucks are cute

Carefull with the Jap comments, my DURAMAX says ISUZU all over it. And I doubt you want to compare a 5.7l vortec to it.

My Diesel IHC Scout had a Nissan 722 6 cylinder engine in it. That thing was a workhorse.

Lots of rigs can pull a v-20, but not all of them can stop so good. Like others said weight is important. I've pulled with an old 1997 land cruiser for years, (it's in my shop now for repairs & I'm bummed) Nothing better, full time 4wd, turns tight and that sucker weighs a ton (or 2 1/2).
Over my career I've towed with anything you can imagine, vans, minivans!, suburbans, jimmy's, s-10's, 4x4's of all makes, brush trucks, and I'd say that the only thing that compares to my cruiser is a suburban, The suburban has more power, but far bigger turning radius. SUV's definitely out pull pickups because of more rear weight. Shorter pickups with 4wd would be my second choice.

All that being said, I live near you & unless you plan to use some of the more primitive sandy launches you should be fine launching & recovering with anything that would tow your rig safely 2 or 4wd, although you probably want to avoid a standard tranny, ramps can eat up a clutch pretty quick.

Couple of the comments remind me of a thread I read on an offroad/bugout vehicle thread on a different forum. Couple of guys were somewhere like the baja or some far off wilderness with their modded out 4x4s carrying gear, hilift jacks, had winches on the front and back etc. They got out to walk a particularly bad section of trail to plan their angles etc and as their walking back to their rigs they get passed by an old native type driving a rusted out '85 2 wheel drive nissan pickup with bald tires and 7 kids under ten riding in the back.