01ssreda4

iTrader: (87)

At the end of the day we are only talking about towing 6k pounds, a 5.3 can do that fairly easily with a little money invested as i stated in my first post. No reason to motor swap or vehicle swap in my opinion.

1FastBrick

iTrader: (17)

This bad boy popped up near me...
https://orangecounty.craigslist.org/...192975241.html

cttandy

iTrader: (12)

I used to own a Yukon XL and regularly hauled well more then what you are describing. The biggest thing you need to do is change from 3.73's to 4.11's. I get burned for saying this, but compared to the pre-LS based motors, the LS format makes it's power much higher in the RPM band. 4.11's will get the power to the ground better in that regard. I took mine through the Mountains pulling 10-12K with no lack of power. My yukon was 4L80E and 4.11's.

By the way, there was a reason they quit selling the 8.1L. It really didn't have an advantage over the 6.0L, and it has a major drinking problem.

Bus933s

Well Im at a crossroad. 4l60e popped the high pressure line out of the radiator on the interstate pulling 6k lbs. Got the rig stopped pretty quick but I think it did some damage. Got the line fixed, filled her back up with fluid and resumed driving home with the trailer. Only now the trans temp is hovering around 190/200 where before this incident pulling the same trailer it barely reached 160 with the secondary cooler. Outside temperature didn't matter. Didn't feel like it was slipping nor shifting hard, but something has happened to raise the operating temp so much, and it was oddly fluctuating a lot, dropping back down to 17ish then back up to 200. It never fluctuated at all when it ran at 160 before this. Taking everyone's suggestions under consideration, now I may have no resale value of my 1/2 ton, and replacing the trans stock is almost what the suv would have sold for. Sooooo. Opinions on the 6.0 in the 2500 burb with the 4l80e vs 8.1? Ill never pull more than 6k/6500, but I don't want to be restricted on where I can tow anywhere in the country. I've also heard the 8.1 runs hot, so a desert trip in the middle of summer may not be a good idea? Also, on the open road could I get better mpg and distance on a full tank with the 6.0 vs 8.1? The 5.3 I was getting 8-9 mpg on a 30 gal tank I was stopping an awful lot. Right now I'm restrcited on funds. I was thinking either upgrade my current, or sell my current and put towards the bigger truck. Now I MAY have zero resale.

1FastBrick

iTrader: (17)

The 8.1 will out pull the 6.0 hands down.
The gas millage difference is minimal and you will probally get better towing milage with the 8.1

We pulled from CA to Michigan and back through Texas non stop in a 2500 truck with an 8.1. Loaded with almost 8000 lbs. We averaged 10-11 mpg and I wasn't easy on the truck either. I may have exceed the speed limit several times too while "passing" a few other trucks that were loaded as well as a semi that thought he could stay in front...

We killed a fuel pump and a water pump on the way back. But in fairness it wasn't my tow rig and I'm not normally the one doing the maintenance.

The 6.0 will get the job done. But the 8.1 will do it much better.