Gobi

First post here and brand new to this whole thing... I tried searching around for a while but couldn't find anything so if this is a repost, I apologize in advance.

I'm looking at getting a 73+ GMC truck and swapping an LS in it. 5.3L seems to be the most popular but what about a 6.0? Are the difference in price that much higher?

What kind of horsepower would I be looking at with each of the engines with a cam and stock heads and (I've read these fit better) a set of the 2010 camaro exhaust manifolds? Would the jump be worth it?

I'm not looking to make a drag truck. Just a street ride that will be fun. Not looking to spend a whole crapton of money either so like stock internals and easy upgrades.

Thanks in advance!

Tuskyz28

Junkyard 5.3 motors sell roughly 500 bucks... I would go that route if you never plan on towing a car or a boat.
Now if you plan on towing any with the truck I'll aim right towards the 6.0 motor.......
what's your budget total for an engine build ?
Remember if you pull both motors out a running car/truck you'll want to give it a little added insurance by replacing or upgrading the oil pump, timing chain, lifters, pushrods and a trunion kit would be nice also...

kelobro

If you have the budget for it, Thompson Motorsports sells a 5.7 (bored 5.3) short block for $1619. A junk yard 4.8 can be had for maybe $250 or less to get the PCM, harness, coils, heads, etc. It would be good to start with a solid, new short block.

Gobi

It's gonna be a show/go/fun truck. The heaviest thing I'll be hauling is my *** and the leaves that drop in off the trees.

I don't really have a budget in mind. All the work will be done myself and parts will be close to cost Due to a family members working at a local chev dealership.

Gobi

as much as I'd love to go that route, I probably won't be able to. I do have some connections to possibly get both of these full setups for fairly cheap.

That said, which engine would I get the best gains from for doing the same changes to each?

conan

iTrader: (5)

If the prices aren't too far off from each other I would go for a 6.0L. If your local junk yards want a crazy amount for the 6.0l, go for a 5.3l.

Tuskyz28

Basing off what you telling us a 5.3 will fit the bill for fine....
Enough power to get the truck rolling good but still have decent amount of miles per gallon if geared correctly....

kelobro

If the 6.0L is even close to the 5.3L price, buy the 6.0L assuming equal perceived quality of the engines (miles, appearance, etc.)

L92 OLDS

Compared to the other LS options (6.0, 6.2. 7.0) the 5.3 lacks low end torque. In a truck that would be my concern. If you choose to go with the 5.3 you could put some steep gears in it to compensate.

Tuskyz28

Truuuuuuuue!! LOL
well the 5.3 is the cheapest way to go and he did say he was on a budget......
plus he also mention he not go be towing/hauling nothing... more of a fun show truck so he don't sound to worry about the low end grunt however I am all for a 6.0 just like you due to just in case he need to tow something he'll have a nice low end grunt.

Gobi

I'm not really looking to change much either on the truck. I haven't got to open it up yet to see what it's got but looking at a stick setup with just a decent cam and some other easy, basic stuff.

have to keep my eyes out for some wrecked savanna or g vans. I have one for my business that has a 6.0L in it. However, short of that getting written off (not hoping for that at all) I'll likely be getting a 5.3L. Unless I find one (6.0L) for stupid cheap or one comes crashing through my front window...

Still wondering what kinda horsepower differences I'm looking at doing the same mods to both engines though. Would help make that decision and see if it's worth the extra money for what I want.

Hypothetically speaking, if I got an engine that is running and wanted to put a cam and some other suggestions you guys think would be good, what kinda money we looking at (without the motor and tranny)?

Mercier

iTrader: (15)

In any given year, there was not much difference between the 6.0 and the 5.3 if we're talking about the regular/affordable variants. I'd say for guesstimating purposes you could just say that the 6.0 is .7L larger.. .7/5.3=13.2%. So you can realistically expect about 13.2% better mod for mod on the 6.0. There are nuances like compression and intake valve size but that also varies by year. Early 5.3s have a slightly smaller intake valve, for instance. I think based on a few hundred dollar difference, just get the 6.0. The LS family shares almost everything so the bolt-ons will run you the same $$.

kelobro

It's a truck. Don't just focus on the engine. It should have a posi rear end with gears well matched to the transmission and engine. Find a 6 speed auto if you can. The 6L80 has nice ratios but only is only rated for 440 ft/lbs of input torque and requires the newer genIV engine. A 5.3L will have no problem getting close to 440 torque with a good cam, tune, and headers. Raise the compression with head milling and/or thinner gaskets. Ask your tuner how much compression you can add based upon the fuel and cam you plan to use.

Tuskyz28

If you score a 6.0 add a tune, long tube headers and a good set of mufflers ..... you'll push out 410 hp/440 tq at the crank with the factory cam..... add a cam and you know it'll increase!!

Gobi

I appreciate all the responses. As far as intakes go, I hear getting rid of the truck one is a good move? Has anybody dealt with the holly ones on summit? They are only a couple hundred bucks.

I didn't really Figure the rear end and gearing into account. Kinda just want to get the motor in for now and go from there But it's definitely given me more things to research!

It's more of a budget build and something tells me that I won't be able to get my hands on a 6 speed auto very easily...

Mercier

iTrader: (15)

The late model truck intakes(4-bolt throttle body) are cheap and flow very well from idle to 6500 IMO. This is the same intake as on the Trailblazer SS LS2(400HP and underrated at that) The earlier 3-bolt truck intakes do not flow so well.

Usually guys get rid of the truck intake because it is taller than the car intakes and won't fit. You have the hood clearance(in your truck), so if you are truly on a budget, save that $$ and get the late truck intake. The metal intakes will also heat soak where the plastic factory ones are much less susceptible to this. I don't think that Holley intake will flow better than the late truck intake for what you are building.

I bought mine off Amazon for $111 because I wanted a brand new, clean intake to start my build with but you can find them cheaper used. Just make sure to get the 4-bolt version. And you'll need a 4-bolt TB or adapter from 3 to 4.

Tuskyz28

Trailblazer SS intake gets my vote here also.....

Gobi

Really? So they got that right eh? Neat.

I've found numerous 5.3L and 6.0L With trannys. Usually go for around 1000 here apparently. Havent Really looked that hard yet into finding write offs or anything yet but I'm optimistic. There's a few full vehicles around that have well over 300,000km but I'm not sure if I wanna head down that road yet.

say I do want to head down that road (cuz obviously getting everything for 1000 is much better... sell what I don't need) what could potentially be required to bringing that motor back to snuff? A full rebuild or just maybe a hone and some new rings or something else?

Gobi

Ok so... definitely just gonna get a write off or something. There's quite a few of the 6.0L cargo vans for sale that have frame damage or something else. Most have around 175000 to 350000 and around 800-1500.

Am I right in assuming the 6.0L will use the same drop-in brackets for the motor mounts that I found for the 5.3L?

Mercier

iTrader: (15)

Same mounts.


Keep in mind the iron 4.8/5.3 can be bored all the way out to a 5.7 bore with no real issues. True LS1s(aluminum 5.7) can't be bored by design. Can hone .005" or so. SO it occurs to me that you have a lot of used LS1 pistons/rotating assemblies out there. Cheap. Pistons break but the rings are the wear items. Unless there is some weird rod incompatibility I don't know about, 4.8 + bore to 3.9" + LS1 rotating assembly or 5.3 + 3.9" bore + ls1 pistons = iron 5.7. I'd still look for a 6.0 and likely get away with a hone and rings but every engine is different and you'll never get the true history of anything over 75K anyway. This could be a cheap middle ground if you have to take it to the machine shop anyway. My local guy quoted me $275 to bore to 5.7 from 5.3 just last week. (4.8 is same bore and block but shorter stroke)

Also for spec *****, bore is rounded up to 3.9" but I think is actually like 3.89xx or similar. Google knows the exact size.