Preliminary checks when swwpping used LS

[WB72]

Planning a swap into a 72 c10.

Donor 5.3l engine and 2WD trans in hand. Supposedly has 200,000km. (130,00 miles)

Should I disassemble anything prior to install? I'm thinking more for leaking gaskets or seal.

I woul also like to swap cams at this time. What is a good, lumpy, but still daily drivable option?

I will be planning on changing out the oil pan for future clearance issues.

What is the procedure on oil pressure prior to starting it up? I'm not sure how long it has been sitting without running.

[mongocanfly]

We've put em in with comparible mileage and never touched them..but if your worried about it you could check compression...just keep in mind if you start pulling stuff off to check internals that a lot of the bolts are torque to yield..means you have to replace them after one use...you could swap some gaskets out to fix a leak here and there..as far as cams go check out btr cams..they have stage 1, 2 and 3 that sound pretty good..youtube for them ..there's a lot of vids on how these sound

[Aaronoregon]

Every LS engine I buy now I run an autocheck on to verify mileage. I have been lied to by too many guys to trust them. Guys say all the time "Yeah only has 130,000" when really it has 220,000 on it. $15 and 5 minutes of your time. I do a lot of swaps. They are awesome engines and don't require much. Great way to go. Good luck.

[mongocanfly]

how are you checking mileage aaron? Never heard of autocheck is it like carfax?

[68c10airstream]

Look at ALL of the exhaust manifold to head bolts. Notorious for braking off the end bolts. Remove the manifolds, weld nuts onto the broken studs and unthread while still warm from welding. The stock bolts are lock tighted and the welding softens it for a while. Nice to do this with the engine out of the vehicle.

[BR3W CITY]

If your doing a cam, do the timing chain, oil pump, front cover gaskets etc. Its also best to buy a new set of GM Lifters. The o.e lifters all got replaced in the GM parts catalog with a semi-upgraded design, and lifters "should" be broken in to match the cam.

[Aaronoregon]

Originally Posted by mongocanfly

how are you checking mileage aaron? Never heard of autocheck is it like carfax?

If you buy it from a junkyard or a wrecked vehicle on craigslist, etc. they can give you the vin to run or you can just take a picture of the vin plate. If the engine is already pulled, I plug into the pcm with my HP Tuners bench harness and pull the VIN.

[WB72]

With the VIN in hand, will the harness need to be connected to the engine or just the ECM before connecting to HP Tuner?

[WB72]

I have noticed broken exhaust bolts. Are the exhaust manifold gaskets typically reusable?

[WB72]

Originally Posted by Aaronoregon

If you buy it from a junkyard or a wrecked vehicle on craigslist, etc. they can give you the vin to run or you can just take a picture of the vin plate. If the engine is already pulled, I plug into the pcm with my HP Tuners bench harness and pull the VIN.

Originally Posted by BR3W CITY

If your doing a cam, do the timing chain, oil pump, front cover gaskets etc. Its also best to buy a new set of GM Lifters. The o.e lifters all got replaced in the GM parts catalog with a semi-upgraded design, and lifters "should" be broken in to match the cam.

Noted...
I have heard the factory trunnions are weak and should be changed during a cam change as well.

[homemade87]

Originally Posted by WB72

Noted...
I have heard the factory trunnions are weak and should be changed during a cam change as well.

Yes , The needle bearing on oem are bad to come out with higher lift cams . The replacement uses a c-clip to hold them in .

Also there is some reports the replacements are having some trouble . There is some premature wear on the main shaft with the needle bearing wearing the shaft even as little as 12,000 miles and under .

There is another trunion that uses bushing ( straub trunion) in stead of needles . I plan to monitor mine and change them eventually . If they start deteriorating they will put metal thru the engine . I definetly would not put the needle bearing ones in a daily driver .

[Aaronoregon]

Originally Posted by WB72

With the VIN in hand, will the harness need to be connected to the engine or just the ECM before connecting to HP Tuner?

With the VIN in hand you don't need anything but access to the internet, If you don't have a VIN you can plug an HP Tuners benchtop harness directly into the PCM and see the VIN on the PCM at home on your kitchen table. Obviously this is if you know the PCM came from that engine. By law the wrecking yard have to have a VIN number attached to any part they sell, but this doesn't stop them from lying to you about the mileage. It is illegal for them to do this, but it is your word against there's they told you wrong. I just always check now on my own. Just last year I had a wrecking yard tell me a 5.3 had 104K on it. About two months later when I went to tune it I ran the VIN and it had been totaled by insurance at 144K. Bastards.......

[72blu]

I agree with everything said in this thread so far. Change the O-ring that seals the oil pickup tube to the oil pump. They often go bad and will result in poor oil pressure. Also, in regards to a camshaft, I used the ASA camshaft in my Lq9 and I love it. Got it over the counter from GM.

[suburban99]

I put new front and rear main seals, pan gasket and oil pump on my 6.0 swap.
Intake gaskets and exhaust gaskets. Also fixed all the broken exhaust bolts..this one has only 1 but last one had 3.

[WB72]

Is it nessisary to pressurize the oil system after a cam change? What is the best way to.do that?

[Aaronoregon]

Just lube it up good and install it. I just fired a 5.3 that has been sitting on the floor on a pallet since 2009. No issues at all. You can always crank them over a few times with no power to the coils first too.

[BR3W CITY]

Originally Posted by WB72

Is it nessisary to pressurize the oil system after a cam change? What is the best way to.do that?

They sell a priming tool. Its not a bad idea, but not strictly "required". I too have done it without. The biggest thing to worry about is (if you used a variety of assembly lubes while building) making sure that the thicker lubes don't clog oil passages. Pressurizing before start helps fill and clear the oil passages before the engine runs.

Like I said tho, I too have done it without and there was no catastrophe.

[Jstock85]

Brew City What kind of priming tool are you talking about?

[Twisted78SS]

There are numerous ways and many will tell you, it all depends on what you want to invest either time and or money..

Here's a google link with tons of examples.

https://www.google.com/search?q=LS+p...p+priming+tool

Even a bunch of videos on Youtube https://www.youtube.com/results?sear...e+priming+tool

As mentioned, it's a good idea but even GM crate engine instructions describe priming without one, so it is a personal preference I guess

[davepl]

My friend uses an old small block oil pump in a steel box he made with a drill attachment - it has an -8AN fitting coming out of the oil pump that he plumbs into the block, spins the pump with a drill, and tada... primed.

Works pretty well for home made!

I've never gotten an LS motor to prime with the starter. I think it's probably worse than nothing doing that.

[Jstock85]

Originally Posted by davepl

My friend uses an old small block oil pump in a steel box he made with a drill attachment - it has an -8AN fitting coming out of the oil pump that he plumbs into the block, spins the pump with a drill, and tada... primed.

Works pretty well for home made!

I've never gotten an LS motor to prime with the starter. I think it's probably worse than nothing doing that.

Ive seen those as well. A guy used a jug of oil connected to the filter outlet and a return from the pump i think. can't remember exactly... spun the drill for a couple minutes till oil hit the rockers and it was ready to go.