5.3 vs 6.0 opinions???

[1972BackInBlackC10]

what would be the better motor to go with? car or truck engine? long or short block, aluminum or steel block, what years etc

im new to the while ls thing so i know nothing about any of it but i would like to learn and put one in my 67

[black_sheep454]

Depends on what you want the end result to be. The f body/corvette motors are the most common aluminum blocked lsx motors but there were a few 5.3 trucks with aluminum blocks. (L33 code I think on trucks) if you just want a good solid motor for a driver it's hard to go wrong with a iron block 5.3, the 6.0's make a little more power and torque but cost more. With the right gear ratio a 4.8 will do fine for a driver truck and can be picke up even cheaper. Hope this helps you out.
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[robnolimit]

Lots of choices. For most, a 5.3 iron truck motor is fine. To match it's performance you would spend 5 or 6 grand on a small block, and never get the mileage. If you go 6.0, look for an LQ-4, they have floating pins. Aluminum blocks cut 65 lbs, and are good for mild to mid HP builds under 500 HP. But, the alum blocks suffer from the cranks walking around, and have been known to loose cam bearings as well. For big HP, 500+, and power adders, I'd go back to the iron block. We have seen these motors go past 800 HP with stock crank and rods, but they do need good bolts. - ARP.

[468BIGBLOCK]

Originally Posted by robnolimit

Lots of choices. For most, a 5.3 iron truck motor is fine. To match it's performance you would spend 5 or 6 grand on a small block, and never get the mileage. If you go 6.0, look for an LQ-4, they have floating pins. Aluminum blocks cut 65 lbs, and are good for mild to mid HP builds under 500 HP. But, the alum blocks suffer from the cranks walking around, and have been known to loose cam bearings as well. For big HP, 500+, and power adders, I'd go back to the iron block. We have seen these motors go past 800 HP with stock crank and rods, but they do need good bolts. - ARP.

the LQ4 6.0 has pressed in wrist pins and dished pistons. the LQ9 6.0 has floating wrist pins and flat top pistons. the l33 aluminum block was produded 2005-2007. also an aluminum block lh6 was produced 05-07 in the trailblazer and envoy. in 07 gen4 engines you can get a aluminum block as well it was the lh6 or flex fuel version the lc9, you could also get a aluminum block 6.0 in 07 and later trucks the l76 also the l92 truck engine isa 6.2 with aluminum block. I have a 04 lq4 salvage yard engine with dished pistons that made 496 horse power with a mild cam,long tube headers and a tune.

[C10_ustacould]

There is no replacement for displacement! lol

[1 Low 70]

How can you tell the difference between the lq4 and lq9?
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[468BIGBLOCK]

Originally Posted by 1 Low 70

How can you tell the difference between the lq4 and lq9?
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the vin number is stamped on the engine block the eighth digit in the vin tells the engine code. the lq4 the vin is U with lq9 the vin is N if ya cant find it you can pull a spark plug and look in for the flat top piston on the lq9 or the dish on a lq4 i hope this helps.

[silverad03]

Hi - I'm barely a lurker (looking through the forum and trying to decide whether to restore my first vehicle - a '71 2500 GMC, but that's another story), but thought I could chime in with some helpful FYI on this topic based upon my own painful experience. Please excuse my lack of forum etiquette...

If you are thinking about a 5.3 be wary of the 5.3L engines GM put out between something like 1999 and 2007 or so (maybe later). One of the manufacturers GM used to cast the aluminum heads down in Mexico had QC problems that resulted in a "porosity" issue and the heads are known to crack along the edge of the shoulder where the head bolt seats in the head.

The name of the outsourced manufacturer of these heads was Castech and the only way I ever heard to tell the engine has Castech heads is to pull the valve covers and remove the valve brace to see if the Castech logo was cast into the head.

Apparently not all heads on the 5.3 engines were made by Castech, so not all will have the issue. Additionally, not all Castech heads will necessarily crack, either, but if you have them they are a time bomb - mine did not crack until I had well over 100k on the clock. From what I understood when I was researching this, there was no definable period of time or production run that was of particular note where you could reliably exclude a range of casting numbers - which suggests the problem was systemic and was not corrected by GM or Castech.

I found this out because on my '03 1/2-ton with a 5.3 I kept getting a low coolant alarm but no coolant was finding its way out of the engine or onto the ground. I pulled both valve covers and it looked like a carmel factory in there from the water in the oil. I started researching the issue and found that even though the Castech heads cracking is not happening on a majority of these engines - it is still happening much more than just a few isolated cases. Mine had an LM7 engine, but it may not be limited to just the LM7 version of the 5.3.

According to what I read, the 6.0 heads were of a different design and/or manufactured elsewhere and the porosity problem does not appear to be a problem in the 6.0's. After reading as much as I could about this, I traded up to a 3/4-ton and got more truck than I needed just so I could stay clear of this issue.

Just something to consider.

[C10_ustacould]

Wow, good to know! A girl at work has a 4.8l doing the same thing, I wonder...

[68short]

Actually the LQ4's had pressed pin's until around 2005 when they went to floating pins. I've seen some 04 LQ4 with pressed or floaters

[68short]

Although Im building a turbo LQ4 for one truck, the other one will get a 4.8, its a great little motor, and there cheap

[dhaymaker]

I've been doing a little research, here and there, on the LS motors. In my '72 (Looks-like-a-'68 Chevy) GMC is a 5.3 with a 4L60E. It has a little valve train and head work, set of headers, and runs really well (around 400 - 405 horsepower). Setting on my garage floor is a 5.7 with a 4L60E from an '02 Firebird. This motor is a low mileage aluminum motor, but to find one like it is around $3,000.00 - $3,500.00 (yeah, I know guys can find "deals", go look for one with wiring, computer, etc.). The difference is, people are finding 5.3 motors in the junkyards or from friends and they are paying a lot less for their motors. It's up to you, I snagged this motor because it was a reasonable deal, really complete, and I knew some of the history and I knew the PO. Guess it's all up to what you want!

[1972BackInBlackC10]

well i found a 6.0 from an 06 silverado 2500 HD for 600 bucks it comes with the injectors but no harness, the bad thing is it has a blown head gasket

should i be leary and stray away or should i get the serial number and pics?

i would like to have around 400-500 HP with the possibility of maybe adding a super charger in the future, by the sounds of things the 6.0 is the best betfor this?

also thought on transmissions? thanks everyone for the help and info

[usmcchevy]

Check out the LSx swap sub section: http://67-72chevytrucks.com/vboard/f...play.php?f=206
There is also a link to the LSx swap FAQ in my sig.

The heads that were cast in Mexico were 706 casting. They were a sand cast head and some say were good for a few more HP than the 862 head. This doesn't say much, but I haven't seen ether head fail unless there was a very good reason.

1972Backin Black, For that HP level I would stick to a TH400 or 4L80E, unless you want a stick, then NV4500 or T56.

[468BIGBLOCK]

Originally Posted by silverad03

Hi - I'm barely a lurker (looking through the forum and trying to decide whether to restore my first vehicle - a '71 2500 GMC, but that's another story), but thought I could chime in with some helpful FYI on this topic based upon my own painful experience. Please excuse my lack of forum etiquette...

If you are thinking about a 5.3 be wary of the 5.3L engines GM put out between something like 1999 and 2007 or so (maybe later). One of the manufacturers GM used to cast the aluminum heads down in Mexico had QC problems that resulted in a "porosity" issue and the heads are known to crack along the edge of the shoulder where the head bolt seats in the head.

The name of the outsourced manufacturer of these heads was Castech and the only way I ever heard to tell the engine has Castech heads is to pull the valve covers and remove the valve brace to see if the Castech logo was cast into the head.

Apparently not all heads on the 5.3 engines were made by Castech, so not all will have the issue. Additionally, not all Castech heads will necessarily crack, either, but if you have them they are a time bomb - mine did not crack until I had well over 100k on the clock. From what I understood when I was researching this, there was no definable period of time or production run that was of particular note where you could reliably exclude a range of casting numbers - which suggests the problem was systemic and was not corrected by GM or Castech.

I found this out because on my '03 1/2-ton with a 5.3 I kept getting a low coolant alarm but no coolant was finding its way out of the engine or onto the ground. I pulled both valve covers and it looked like a carmel factory in there from the water in the oil. I started researching the issue and found that even though the Castech heads cracking is not happening on a majority of these engines - it is still happening much more than just a few isolated cases. Mine had an LM7 engine, but it may not be limited to just the LM7 version of the 5.3.

According to what I read, the 6.0 heads were of a different design and/or manufactured elsewhere and the porosity problem does not appear to be a problem in the 6.0's. After reading as much as I could about this, I traded up to a 3/4-ton and got more truck than I needed just so I could stay clear of this issue.

Just something to consider.

I have a 03 suburban with 706 castech heads on it with 263K miles and NO PROBLEMS. I have put one water pump on it both knock sensors and one set of plugs in it in 263K miles these engines are DEAD RELIABLE.

[1967wannabe]

I've been wrestling with the same questions for a couple months now, I've got my eye on this http://www.ebay.com/itm/6-0-engine-L...sories&vxp=mtr combo right now, it's local so I can save the freight, just don't want any regrets.

Do you guys think the price is right?

Seems to be the going rate for a lower mileage LS2/6L80E combo.

[dhaymaker]

This is a similar combination to what I have in the garage. This is a little better motor, perhaps, plus a six-speed automatic. With everything with it, and the low miles, it seems like a good combination. Price wise, seems fairly high. But, when I first started looking around, I was finding guys trying to sell just the motor for $2,500 and up. One thing about it, this thing should motorvate a '67-'72 quite nicely!

[gvnick]

For our trucks, the truck style accessories fit perfect, so I would go with a truck motor and get the alternater and PS pump in one shot.

I like the 5.3 for a daily driver. Bone stock they make great power. To compare I pulled a healthy 350 with a mild cam out of my truck, and the 5.3 has noticably more power everywhere.

If you plan on doing a cam and other performance mods, then you might as well start with a 6.0. IMO