5.7 vs 5.3

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JollyGreen

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I sold my 05 Yukon Denali last year because my wife wanted something with a little better mileage. I regretted it when I sold it, wife regrets it now. That thing stock had some balls, and I can imagine with a little work it would flat out scream. Those 6.0's have tons of untapped power. Like NacIK said, only problem is price.
 

NacIK

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Yup. If I became rich somehow you could safely bet on me ripping out my L31 and installing a tuned up 6.0.
 

SAATR

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My 6.0 is an LQ4 out of an 04 2500HD, complete from pan to intake with sensors, harness, and ECM. Cost me 1500 shipped. Would have been 1100 without freight, but I could only find longblocks locally. They are rare in the local wrecking yards, and don't last long when they're there. You don't need to be rich, and could do it easily and fairly cheaply. .

If you bide your time and check out the classifieds on a few LS forums, you could pick up a good cam, lifters, pushrods, and intake on the cheap and have an absolute screamer. Just be prepared to buy some tuning software and a wideband and start climbing up that learning curve.

My own project has been put on hold due to funds availability (read: I'm broke) but will recommence very, VERY soon.
 

MOBS

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Oh this looks like an interesting thread....I see someone asked about a direct bolt-up from a vortec to a 366? Haha....you would need to replace those heads&cam and blow that engine to create ANY power. But, so long as your tranny uses the standard bolt pattern, it would be a "direct bolt up". Ofcourse if you used the later model engines, you would be switching from mpfi to tbi.

Also, in case anyone is curious, the LS 6.0 is a 364ci(same as in GTO's), not 366, and the LS 5.3 is a 323, not 327. I hear alot of salesman telling people that "the 5.3 is an upgraded 327"....I almost want to throw pebbles at them for lyin' like that!!!
 
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SAATR

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Also, in case anyone is curious, the LS-6 is a 364ci(same as in GTO's), not 366, and the 5.3 is a 323, not 327. I hear alot of salesman telling people that "the 5.3 is an upgraded 327"....I almost want to throw pebbles at them for lyin' like that!!!

The LS-6, like the LS-1, is 346 cubic inches. ((3.898bore)/2)^2 X pi X 3.62stroke X 8 = 345.7 or approximately 346 cubes. The GTO's came with both the LS-1 (not the LS-6) and the LS-2, which is a 4.00 inch bore. The same math with a 4.00 inch bore (LS-2, LQ4, LQ9) and a 3.62 inch stroke gives 363.9 or approximately 364 cubic inches. While the BBC and the LS motor have a couple of cubic inches displacement difference, they both are still considered to be 6.0L motors, hence the confusion and clarification.
 

MOBS

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I completely botched that, I was using LS-6 to refer to the 6.0 engine, not the actual LS6 engine....sorry for the confusion. I'll edit it in a jiffy.
 

felon637

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My 97 K1500 5.7L 3.73 gears and 285/75/16's has trouble hauling an empty 16ft utility trailer. I run 70mph down the interstate in 3rd gear and it is a freaking dog. Going up a hill is like hitting a wall.
 

97_chevy

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i had i 350 man and just put a 5.3 in my truck and its a big diffrence alot more power with 5.3 man are trucks are real light 5.3s can make alot more power with the right parts i pick a 5.3 hands down
 

borahshadow

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My 97 K1500 5.7L 3.73 gears and 285/75/16's has trouble hauling an empty 16ft utility trailer. I run 70mph down the interstate in 3rd gear and it is a freaking dog. Going up a hill is like hitting a wall.
My truck is identical drivetrain wise. I just got done pulling my 29' camper almost 1000 miles and up and over the continental divide almost 5-6 times throughout the trip. Honestly I was pleasantly surprised how well it did. Sure I wasn't setting any land speed records or anything but on the flat without a head wind I could pull 70-75mph. Going up the hills I had to resort to 2nd gear some times but I have to do that sometimes in the 5.3 suburban with 4.10 gears that I usually pull that trailer with. I stopped at a scale and with a partial tank of water I weighed a little over 12k truck and trailer. I got about 8mpg when I had the trailer in tow which is about what the suburban I mentioned gets with the same trailer. IDK how much more the suburban weighs but it does weigh more so that is part of the reason that it doesn't do too much better than my truck.

I've never driven a 5.3 with the 3.73 before so I can't compare that. These are both stock motors so since the 5.3s are easier to build up that is a major plus for the 5.3. I think a 5.3 wins but stock vs stock if it's geared right I don't think the 5.7 is incapable of pulling a decent load. I still think that the 5.3 is better but it's still no duramax.

On a side note I think I want an 6.0 when my 5.7 expires ( LQ4 or maybe and LQ9 if I want to convert to drive by wire and can find one) That would pull great I think.
 
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