jbaum02

I have a 2005 1/2 ton GMCSierra Z71 that has a 5.3 L33 engine. The truck has pretty high miles and it's beginning to have oil pressure problems. So I decided it was time to start an engine replacement. Since this will be my first attempt at engine work, I could use some advice on some of the plans and mods I'm thinking about.

A little more about my truck:
ECSB
5.3 L33
4L60E Automatic
6" Suspension Lift
325/60r18 tires (33" OD)
4.56 axle gears

I recently purchased a complete 2005 LQ9 6.0 pullout from an Escalade with only 43K miles on it. The engine looks really clean and seems to be in good condition as it turns over smoothly by hand.

So far I currently have:
6.0 LQ9
Computer from the 6.0
TBSS intake, throttle body, and injectors
Torque Rush X-link harness to run the TBSS throttle body

I'm thinking that I'd like to add a few mods while the new engine is out of the truck and things are easier to get to.

Other things I'm considering adding during the engine swap:
Long Tube Headers (if I can figure out a way to keep the catalytic converters and pass inspection)
A camshaft and stall converter( I don't have anything picked yet, but I want to keep it somewhat daily driving and towing friendly)
Possibly replacing the current 317 heads on the LQ9 with the 799 heads off my L33.

My questions are:
1. With around 43K miles on the 6.0 would you pull anything apart to check it out before swapping it into the truck?
2. If you were going to swap the cam while the engine is on the stand, would you pull the heads and replace pushrods, lifters, etc. or would you leave all of that stuff alone?
3. If I do pull the heads to do the cam swap should I rebuild the 799 heads from my current engine to use on the 6.0? I read that it will raise compression and add some power, but it will add cost and time to the engine swap. Is it worth it?

XBlackXCheavyX

iTrader: (1)

1.if it was me I would go ahead and replace the bearing while I had it on the stand, with 43k they probably aren't in bad shape but adds some peace of mind on down the road if you decide to put the power to it..

2.As for cam swap, when i did mine I just replaced the springs and push rods, left the lifters alone and my engine had more miles on it, so nI need to pull heads unless you want to replace them..

3. As for heads you'll have to let someone else help you, can't help you much their.

zero2sixT

iTrader: (4)

When I bought my used LQ9, I didn't pull anything apart. It had been sitting for a year in the seller's garage. It was a pull out from a rolled over escalade w/ ~65k miles. It sat in mine for almost another year. To this day, it has the original lifters, timing chain, and oil pump. Runs great, made decent power, and is relatively quiet. When we swapped the cam, we didn't use anything the hold the lifters in place. Had no issues with them dropping.

If you want to keep it N/A, definitely swap the 317s for the 799s. Do a little bit of searching, the work is worth the power bump; especially with the 90mm intake. When you do that, if it makes you feel better, drop in a new set of lifters and trays. You will get new pushrods with the cam kit you buy. Use LS9 headgaskets.

1994Vmax

iTrader: (4)

I would pull the engine apart and check everything...... I have had enough of junk in my life that I don't trust a thing...... I would do the same with a brand new crate..... be prone to do moreso with a crate as they are pretty shoddy.

I would check taper in the cylinders, bearings and crank surface ( rod, main, thrust) and the cam bearings. I have a 40000 mile LQ9 sitting here that I have had for 5 years now and when the time comes to use it that engine is coming apart before I put it into anything...... plus it will get a cam and heads at minimum anyhow lol.

Wolftrk99

iTrader: (5)

If youre going to pull heads, swap the lifters, i wouldnt bother swapping ecms either, gonna have to be tuned and vin to match either way..... Longtubes with cats are fairly easy.... My suggestion keep it simple get an ory with the headers and cut enough off the header and ory to allow the cats to slide into place(wishing i had) or you can spend the money for a set of arh or kooks that have catted ypipe.... Checking the bearings and throwing ag very keast an oil pump and a fresh gasket set on a used engine is always a good idea, unless you drove the vehicle and then pulled the engine dont trust anyone, but yourself....

zero2sixT

iTrader: (4)

Wtf? So you would spend the extra money on a low miles JY engine or even more on a crate, then pull it apart?

Op, do not do that ****.

Wolftrk99

iTrader: (5)

Depends where the "crate" engine came from.... Have had issues in past with reman "crate" engines having different bores.... three cylinders were stock bore and the rest were anywhere from .010-.040 over..... I see 1994vmax's point but a "good" used engine still needs to be checked especially if the condition is unknown

jbaum02

I've talked to a few people now that agree that the head swap is worth it while the engine is out so I'll most likely plan on that. What's the deal with the LS9 gaskets? I thought that engine had a bigger bore diameter than the 6.0?

I agree that it's hard to trust something with an unknown history. But I did pay more for a low mileage engine that I was hoping wouldn't have to have a rebuild on. With this being my first significant engine work, I'm confident I can do the head and cam swap myself. I'm not sure if I want to try tearing down the short lock by myself and taking it to a machine shop would probably add to the overall cost.

Maybe my question should have been...With the heads and front cover off and the cam out are there any red flags I should be looking for? Besides obvious damage are there any wear patterns that would signal something is wrong and would require a more in depth tear down?

Wolftrk99

iTrader: (5)

Wouldnt say tear it down completely just throw a set of bearings in the bottom end....gives you a chance to make sure they arent scored while youre there

zero2sixT

iTrader: (4)

The bore size isn't an issue. They are good headgaskets and will give you some security if you decide to boost it. Make sure all gasket material is scrapped off before putting the heads back on. If you're going with headbolts, take time to ensure all the bolt holes are clean and dry.

Look for an excessive slack in the timing chain. Don't mess with the oil pump. Change out the oil pressure sensor that is located behind the intake. If you see a lot of sludge build up maybe dig deeper.

Some ppl use dowel rods to hold up the lifters in case one falls while the cam is out. If you're changing them out then don't worry about the dowels.

Search out ls1 tech how to. That site will clear everything up.

Good luck man, should be a nice running truck when you're all done.