Best LS for 1/2ton "work" truck?

[yossarian19]

So, I realize this is inviting a lot of controversy, but..
For a 1/2 ton work truck (not a hot rod, not a drag racer, not a full ton horse-trailer-hauling monster) which LS is the best bet?
The 4.8 makes almost twice the power of the stock I-6, so it should be fine power wise.
The 5.3s make more power but I'm not sure if they'll get better or worse fuel economy in a 3400 lb truck.
The 6.0 seems like it would be overkill, but maybe not?

When done, the truck will be used to help college kids move on the weekend (side work = spending cash), haul loads of fire wood, or maybe once in a while to tow but probably never more than 5K lbs (and even that is a stretch, as I don't currently own anything I'd need to tow). When the truck is done, I'll start on an in-bed camper project - 1000 lbs or so.

So for the duty I have in mind, and recognizing that MPG is meaningful here, which LS series engine do I want?

[Divine 59]

The 4.8 is marginal in a modern truck if you do any type of towing. The 6.0 has had some issues with oil consumption and piston slap. I don't see a big fuel consumption penalty between the 4.8 vs 5.3 motors. If you are going to go LS I would get a 5.3, others that have actually done the swap may have a more informed opinion.

[Amorget]

I' just see what you can find cheap in your area. If the 6.0 costs the same for you as the 4.8/5.3 I'd get the 6.0.

[cajundragger]

get whatever you can. Any of the truck motors will be plently, as well as a ls1- 5.7L.

the 4.8 would be fine and that is probably the cheapest.

[thump16]

earlier 6.0's had piston slap. I would think any of those engine would suit your needs. the 4.8 comes in a variety of heavier GM vehicles so that shouldnt make ahuge difference. Ask more questions in the LSX forums.

[low67chevy]

LQ9 6 litre alum block and heads 350+hp stock lots of torque came in some avalanches and escalades

[thump16]

I am currently building a 84 c10 with a LQ4

[G&R's57GMC]

I doing a 5.3 in my '57

[c6_rob]

Originally Posted by thump16

earlier 6.0's had piston slap. I would think any of those engine would suit your needs. the 4.8 comes in a variety of heavier GM vehicles so that shouldnt make ahuge difference. Ask more questions in the LSX forums.

This is true in some 05's. I have a later model 6.0 LS2 in my Vette and it runs like a champ. With some bolt ons a little porting and a tune im making 430/410 to the wheels. Id go with the 6.0 also because it all aluminum as well.

Go with a Z06 clutch and add a remote bleeder if your going manual.

If you can find a 6.2 LS3 its about 30 more hp than the LS2 but its a tad more $

Feel free to ask me any ?'s

[OKGMC4]

I went with a 5.3 that I got complete with all accessories , trans, and wiring with ECM for $1200. I've seen a 4.8 engine with a 4L60E for $700. You won't find a 6.0 for that usually. Would that be cooler? Yes. But the original post said not a race car or horse hauler so the smaller engines should work fine. Especially if money is an issue.

[chevyrestoguy]

It depends on your budget. You can't go wrong with any LS motor, in my opinion. I've seen complete 4.8s sell for incredibly cheap. It's like nobody wants them, which is good for us hotrodders.

[yossarian19]

I've only got $500 a month or so to throw into the project. I'm not inclined to buy a crate engine because of cost. I'm not inclined to buy a used aluminum block engine because once it's done, you can't bore it - it either takes a hone & rings, or you buy a new engine. (right?)
I think an iron block 4.8 or 5.3 is the ticket for me. Cost will probably decide it.
Do I need to run any particular header for clearance with these motors? I've heard people mention the Trailblazer SS headers but can't find much info right now.

[G&R's57GMC]

I'm using a set of block huggers from Sanderson Headers on my 5.3 in my '57.

You can mill the stock headers with a 5 to 7 degree angle shaved of the mating surface to allow the header flange to suck in and clear the chassis.

[1project2many]

We've got several 6.0s in our fleet and they're really a waste of money for us. The vehicle isn't more than 50% loaded most of the time and even at max capacity they're only near 80%. Yet we're paying the penalty of the large engine with 7-8 mpg averages. Wish we could go with a smaller engine but GM doesn't offer the chassis with anything else.

When people say the small engine is marginal when towing, they seem to forget just how much has been towed with engines making less than 150 hp over the years. In many cases you'll have plenty of gear in an old truck to pull the load you want to pull as long as you're not trying to run down the highway at 80mph. And if your truck has stock brakes then anything near 200hp will move a load easily enough so you can forget how much extra distance and time it takes to stop anyway. I've played this game a few times over the years and although I don't always follow this route, the safer path is with the smaller engines.

[Amorget]

You are averaging 7-8 mpg with the 6.0L?

[G&R's57GMC]

Remember this is about power to weight ratio.

The 5.3L ,4L60E & 3.73 gears with 31" tires in a Avalanche that weighs over 6,000 # is no slouch of the line. It can pull a trailer up to 7000# easily.

Now put that engine, trans. & gears in a 3200# classic truck and it becomes a hot rod !

So one could get a good buy on a 4.8L with trans and be real happy with the results.

[1project2many]

You are averaging 7-8 mpg with the 6.0L?

Yep. Almost all our driving is stop and go in town stuff. It gets a little better in the summer but those months have the least usage so it's not much help.

[Amorget]

Ahhh, yeah, driving that around would hurt the gas mileage, plus the stop and go.

[69CRUZR]

Our 4.8 LS has a cam headers and ECU reflash to run with the few mods and it runs great! I wish the truck was done so I could tell you how it drives though! But I would say its making roughly 325hp? 290hp stock, then a comp cams camshaft, headers and a free flowing dual exhaust, if its making 350hp id be very lucky. But with the awesome driveability and manners of these engines you would not be dissapointed! People shy away from the 4.8s most likely because its just a smaller number than the 5.3 and people immediately dismiss it as "gutless". But with only a 15hp difference between the 5.3 and 4.8 in the later year aluminum headed engines, its not that big of a deal if you ask me!

[sqrlnts]

Awesome post, I plan on going this route in the next couple of years. Here is a great tech article from Car Craft 99'. The summary is that for around $2700 you can have well over 400 HP. I realize its not your goal but thought I would share anyway.

Its a 5.3L with a GM Performance Parts single-plane intake manifold, Comp Thumper hydraulic roller cam, Holley 750-cfm carburetor, Hooker 13/4-inch headers with a 21/2-inch exhaust system and Flowmaster Super 44 mufflers. It made 433 HP.

http://www.carcraft.com/techarticles...e/viewall.html

[wyomech]

I am running a 6.0 and the power it has compared to my 327 is amazing it does ok on fuel but I have a hard time checking milage because I keep stomping on it running a overdrive transmission makes as much difference as the newer motor. I also enjoy running it at the dragstrip.But for what you are using it for a 5.3 would be a better choice.

[hotrod1]

LQ4. Steel block will last!

[cajundragger]

Originally Posted by yossarian19

I've only got $500 a month or so to throw into the project. I'm not inclined to buy a crate engine because of cost. I'm not inclined to buy a used aluminum block engine because once it's done, you can't bore it - it either takes a hone & rings, or you buy a new engine. (right?)
I think an iron block 4.8 or 5.3 is the ticket for me. Cost will probably decide it.
Do I need to run any particular header for clearance with these motors? I've heard people mention the Trailblazer SS headers but can't find much info right now.

thats wrong.

all the steel and aluminum blocks assemble the same, with sleeves. so when either is worn out, its time for new sleeves.

but

I've personally seen a couple 250,000+ mile ls engines and they are still going with good regular maintenance. If your wondering where, well we service a bunch of guys who hot shot for a living...

With that said I would still just get whatever engine you can that's cheap, which is going to be a cast iron 4.8.

I've never seen a 6.0 get that bad of mileage all the time. My brother has a 2003 1500HD with a 6.0 and a 4L80E(power hungry) and he averages about 14 mixed driving a 8-9 loaded with a 26 foot enclosed.

My 2000 sierra extra cab short bed with the 5.3 gets 16-17 mixed driving and 19-21 on interstate.

My '49 chevy with the ls1/t56 with 4.10 gear and 27" tall rear tires just got 29mpg at 80 on the interstate going to a show. The ls1 is stock tune with exhaust and intake, lean cruise turned OFF.

Its also common for a 6.0 swapped half ton 99-07 chevy truck to get over 20mpg regularly as long as the 4L60 or 4L65 is used.

[steve757]

Originally Posted by cajundragger

thats wrong.

all the steel and aluminum blocks assemble the same, with sleeves. so when either is worn out, its time for new sleeves.

but

I've personally seen a couple 250,000+ mile ls engines and they are still going with good regular maintenance. If your wondering where, well we service a bunch of guys who hot shot for a living...

With that said I would still just get whatever engine you can that's cheap, which is going to be a cast iron 4.8.

I've never seen a 6.0 get that bad of mileage all the time. My brother has a 2003 1500HD with a 6.0 and a 4L80E(power hungry) and he averages about 14 mixed driving a 8-9 loaded with a 26 foot enclosed.

My 2000 sierra extra cab short bed with the 5.3 gets 16-17 mixed driving and 19-21 on interstate.

My '49 chevy with the ls1/t56 with 4.10 gear and 27" tall rear tires just got 29mpg at 80 on the interstate going to a show. The ls1 is stock tune with exhaust and intake, lean cruise turned OFF.

Its also common for a 6.0 swapped half ton 99-07 chevy truck to get over 20mpg regularly as long as the 4L60 or 4L65 is used.

The LQ9- LQ4 are both Iron block truck engines, the different is the pistons and the blocks are not sleeved.

[cajundragger]

your right. I was under the impression that the iron blocks were cast in place dry sleeved like the alum blocks.

either way, I know you can go .010" on the iron sleeves before resleeving so it doesn't seem like you'd wear it out to the point of resleeving without putting a serious amount of heat in it.