5.3 vs 6.0

[chpr1972]

I have both engines. The 5.3 has 4L60 in a running 2003 Burban. 6.0 has a 4L80 and just a blue red computer. Which one should I use? After I bought the 6.0 a couple of my friends stared telling me horror stories of problems with the 6.0! The most I might do is put a stage 2 BTR cam in it. Should I mix and use the 4L60 with 6.0. It is going in a cruiser 66 Lemans conv.

[ryeguy2006a]

What horror stories with the 6.0?? Unless it's a 99-00 6.0 which have a longer flywheel flange and iron heads, I've never heard of a horror story with a 6.0. What are your goals for the car?

[79 Camaro]

I would use the 6.0 and the 4L60E built with good parts. L92 heads on the 6.0.

[SPLATT71MC]

I have 230k miles on a LQ4 6.0 in my 02 Silverado, no issues here.

[Alwhite00]

I absolutely love my 6.0 in my 67 chevelle. LS2 intake, LS6 cam, ported heads.

[JayHizzle]

And let me guess, your friends are running 5.3s? Run the 6.0 with LS3 heads and the 4l80.

[Vimes]

Which you need depends on your goals for the car. Either engine will be fine in general. The 5.3L will do a bit better for fuel economy, the 6.0 has more power potential.

The transmissions will make a difference as well. The 4L60E is a little rubber band POS while the 4L80E is almost bulletproof. The 60 is fine for low power, low weight cars but if you put a load on it the bands will wear and start slipping. The 80 uses actual gears because it's a real transmission. The real negative on the 80 is the gearing as the 80's first gear is the same ratio as the 60's second gear, so the 60 will give you better acceleration from a stop. It also takes more HP to drive the 80 than the 60.

At 3400ish lbs the 5.3/4L60E would do well if you're just doing a cruiser, but I'd have a performance trans company like FLT go through the 60 before running it. 285HP is right at 12lb/HP, which is almost in muscle car (10lb/HP or less) territory. Depending on which 6.0 you have you're starting with between 300 and 367HP. No idea what the cam would do, but you'd likely be under 10lb/HP. If you go 6.0 and 4L60E, definitely get the trans beefed up.

If you decide on the 4L80E, add a low gearset to it. I had one installed and while it is pricey, it's also worth the money. The 2.75 had me taking off right on the verge of spinning, and acceleration in 1st gear was way better than a stock 4L80E. Disclaimer, the set I used was TCI, and there was an issue where it wasn't quite machined right so it took a few back and forths between the trans shop and TCI to make it work correctly. But once it was together it was perfect. EFI Live will allow the computer to be programmed correctly for the gearing.

[Hotwire]

...The transmissions will make a difference as well. The 4L60E is a little rubber band POS while the 4L80E is almost bulletproof. The 60 is fine for low power, low weight cars but if you put a load on it the bands will wear and start slipping....

You make good points but need to reel it in a little as the 4L60E only has 1 band that is used for 2nd and 4th. Issue with the 4L60/700r4 is the small input drum that houses the 3/4 clutch pack. You can build a 4L60 to hold damn near all the power it just takes money to do it. As stated the 4L80e is better for beating but it's heavier, bulkier, and requires more hp. It's a TH400 w/ an extra gear. Think gas vs diesel as far as trans work detail when comparing 4l60e to 4l80e.

Back to subject, go 6.0, you won't be disappointed. The old saying of there's no replacement for displacement is very true.

[SinisterSpeed]

Sounds like you have some very detailed info here.
My only experience with these two engines were in 4wd trucks.

2001 4wd CCSB w/6.0 4L80E 6" lift on 35's w.4.10 gears. It ran flawless did everything I ever asked it to do without any issues.
I only had 2 complaints specifically in the application I was using it caused:
1. 9-10 Mpg unloaded, 6.74 towing 9k trailer. I never did any upgrades on the engine because I didn't want to loose the reliability and I was unexperienced at the time what was actually safe to do.
2. Just didn't have enough power when towing. Over hills I'd get down to 25-30mph even with 4.10 gears.

In 7 years 100k miles I only fixed an idler that started squeaking and the fuel pump went out.

Truck was totaled, I almost bought it back to get the drivetrain for another project. I replaced it with the almost exact same truck 2004.5 CCSB 8" lift on 37's but with a Duramax.
For what I use it for, it was the right move. Now same trailer, same road I leave it on CC at 65 and it never slows down, gets 12-16mpg towing and 18-21 unloaded.

But I wouldn't hesitate for a second to use a 6.0 in any car, a few upgrades and it would be a phenomenal power plant.

Now my dad had almost the identical truck but a 2006 4wd 1500 with a 5.3 (I assume 4L60). Truck felt faster than my 01 with 6.0, and butt cheek dyno it felt like it had more power.
He drove that until 165k miles and sold it without any issues at all.

After reading the above comments, makes total sense it was the first gear in the trans that made it actually feel quicker when it really shouldn't have been.
HP numbers were very similar, TQ was higher gears were also lower in my 6.0.

Both power plants are great engines, If I had to make that choice, I wouldn't hesitate to use whichever one has lower miles.

[Vimes]

You make good points but need to reel it in a little as the 4L60E only has 1 band that is used for 2nd and 4th. Issue with the 4L60/700r4 is the small input drum that houses the 3/4 clutch pack. You can build a 4L60 to hold damn near all the power it just takes money to do it. As stated the 4L80e is better for beating but it's heavier, bulkier, and requires more hp. It's a TH400 w/ an extra gear. Think gas vs diesel as far as trans work detail when comparing 4l60e to 4l80e.

Heh heh, I don't think so, especially since you went on to agree with me. My experiences with the 60 over the years have been rather unpleasant, and I've had to replace more of them than any other trans I've ever run. GM agrees, because there's a ton of torque management in the stock programs for 60-equipped vehicles and the they stated it was for trans longevity. Without it, the trans wouldn't outlast the warranty/ The 60 needs a lot of upgrades to match the ability of a stock 80. If someone wants to run a 60, that checkbook really needs to come out especially if any beating is in its future. But, just my opinion, if anyone likes the 60 I'm fine with that.

[Vimes]

Sounds like you have some very detailed info here.
My only experience with these two engines were in 4wd trucks.

2001 4wd CCSB w/6.0 4L80E 6" lift on 35's w.4.10 gears. It ran flawless did everything I ever asked it to do without any issues.
I only had 2 complaints specifically in the application I was using it caused:
1. 9-10 Mpg unloaded, 6.74 towing 9k trailer. I never did any upgrades on the engine because I didn't want to loose the reliability and I was unexperienced at the time what was actually safe to do.
2. Just didn't have enough power when towing. Over hills I'd get down to 25-30mph even with 4.10 gears.

In 7 years 100k miles I only fixed an idler that started squeaking and the fuel pump went out.

Truck was totaled, I almost bought it back to get the drivetrain for another project. I replaced it with the almost exact same truck 2004.5 CCSB 8" lift on 37's but with a Duramax.
For what I use it for, it was the right move. Now same trailer, same road I leave it on CC at 65 and it never slows down, gets 12-16mpg towing and 18-21 unloaded.

But I wouldn't hesitate for a second to use a 6.0 in any car, a few upgrades and it would be a phenomenal power plant.

Now my dad had almost the identical truck but a 2006 4wd 1500 with a 5.3 (I assume 4L60). Truck felt faster than my 01 with 6.0, and butt cheek dyno it felt like it had more power.
He drove that until 165k miles and sold it without any issues at all.

After reading the above comments, makes total sense it was the first gear in the trans that made it actually feel quicker when it really shouldn't have been.
HP numbers were very similar, TQ was higher gears were also lower in my 6.0.

Both power plants are great engines, If I had to make that choice, I wouldn't hesitate to use whichever one has lower miles.

Your 2001 was only rated for 8500lbs in that config, with stock size tires. And, with the 35s, your 4.10s effectively became 3.57s which dropped your towing ability, so the truck actually did well. You would have needed a 4.70 ratio to get the towing ability back. 9000lbs, that's really diesel territory anyway, which your experience showed. And, unless there were any unicorns out there anything with a 5.3L came with a 60. An 80 with the low gearset I linked will feel just about as fast but it's going to set you back that 1200 plus rebuild cost.

[slazisme]

I vote for the 6.0L with LS3 heads. I just finished mine with a mild cam in Nov. Took it out to fill it up with gas, maybe put 5-10 miles on it.....dying to take it out but its cold here now.
https://www.youtube.com/watch?v=frXtdwXsweY