My '02 Yukon with a 6.0 swap, Z06 cam, 3.73s, and 32" tires got 16-17mpg. Better than the 5.3 that came out of it. My L76 in my G8 got up to 25mpg with the DoD tuned to be more functional. Both of them made right at 375rwhp.

Hell, my 428 stroker in the G8 now will get 18mpg on the highway at a steady 80mph. I average around 12-13mpg in it mixed city/ highway.

A heavy *** 3/4 or 1-ton, especially 4WD isn't going to get **** for gas mileage, so matter what you do to it.

 

The Z cam isnt made for towing, hauling or being used in a heavy truck. If you had a cam with a powerband suited to the truck intake and shift points of ~5600 wot youd see a pick up in power. More lift less lsa.

 

The 6.0 truck engine had the square port heads on 08 up 2500HD.

 

Well no one makes a PROVEN towing cam for LS motors. If they do I haven't seen one. Otherwise looking in jegs and summit racing you'll see cams specified for towing, 4x4s,hauling etc.....

 

TSP/BTR they have cams that are set up for towing.
The issue is people not stopping at "stg 2"
Above those normally you lose the low end grunt necessary and the power band goes above the reg rpm youd need it at.

 

That's the LY6 motor. It has variable valve timing. It generated 361 horsepower at 5,600 rpm and 385 lb-ft of torque at 4,400 rpm using "regular" gas, or ~87 octane. Redline is 6,000 rpm and compression ratio is 9.6:1. This engine uses L92 / LS3 style rectangle port cylinder heads, though without the sodium filled exhaust valves of the LS3.

More power than high output LQ9.

 

So you think a aftermarket cam will out perform the factory cam from idle to 3000 rpm. Towing range....
If so I'll like to see a dyno graph. Remember when towing idle torque is what you need to get your camper/car/boat/bails of hay moving.

 

Youll never see a dyno graph of that. Im sure you are aware of the reasons why.
The potential is there but only a calibrated butt dyno could tell you.

 

https://ls1tech.com/forums/dynamomet...hp-22rwtq.html

Good thread here. I am heavily considering one of the Cam Motion drop in cams for my LQ4.

 

Results would be different in a LQ4 vs the 5.3 that was used in the thread. I remember Hot Rod Magazine bolted on a set of headers, mufflers and a tune. Those simple 3 mods put the 6.0 over 400 horse at crank.

 

That's the best 6.0 gas milage posted in thw thread so far. Im impressed with those numbers.

 

I understand that. However, similar gains would be had with their 6.0 cams as well. I have spoken with Cam Motion and it was said that I would pick up noticeable off idle/midrange power with one of their cams.

 

I vaguely remember hearing about this nelson harness. Can you elaborate on what it is and where to get it?

My radiator fits good, truck came from the factory with an oil cooler and big alternator with twin batteries. My metal fab buddy made some simple brackets to hold the f-body fans to the rad support, the setup almost looks factory.

 

Idle to 3,000 rpm is exactly where a factory 5.3 makes no power. When towing it is entirely gutless until about 2,800 rpm then it feels like a turbo kicked in. My 5.3 is a very poor truck engine. I have a rebuilt LS6 for it, also a poor choice but the price was right. At least I'll be adding displacement and shedding weight.

 

Yep. The 5.3 has no torque down low at all unlike some of the motors I already mentioned earlier in this thread. The only solution to fix that problem without removing the motor would be gears in the rearend and a tranmission with a strong first gear but then you'll be spinning the motor higher going down the highway as well. My dad is over 70 and told me back in his day the granny low tranmission was the hot ticket for guys looking to tow they camper etc...

 

I would love to see the results if you do so. I'm surprised Richard Holderner havent built/dynoed a 6.0 motor with a cam like you mention. Maybe I need to hit him up on Facebook.

 

The 6 speed was a big improvement for towing quality. Always seemed to have a happy medium gear. With the 4 speed it seemed to be revving way to high or lugging way too low

 

Even worse if you listen to the hot rod magazines and put a LS6 cam in a 5.3. Ask how I know.... Back before I really understood these things.

I very seriously considered doing an all stroke 6 Liter. Keep the 3.78 bore and throw a 4" crank in. For my Suburban. I ended up putting the money to better use, but if I ever pick up another truck that I intend to tow with, that'd be my plan. keep the 706 heads on it and let the added stroke bump compression up close to 11. Ditch the clutch fan and maybe even do a EWP.

I'd be very curious how that would do on gas vs the 4" bore, 3.6 stroke OE 6L. I'm sure it would be torquier, but a turd after 4500 RPM.

Also, out of curiosity - anyone think hydroboost adds a drain to the motor vs regular power steering?

 

Are a set of long tubes a worthwhile expense for my 2500HD?

Towing, mileage, fun....

 

Nelson Performance makes it. We do sell them. Uses the pcm to trigger fans based off ect low or high and off ac command.
The wide radiator not only cools better but opens up the inner core support holes for the stock truck fans to bolt to.