LS3 swap

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Apr 25, 2008 | 12:27 PM

406 Q-ship

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LS3 swap

Here it goes, I have been thinking about this for awhile now and am just about to take the leap.

I'm thinking about a GMPP LS3 crate engine in a 1971 Monte Carlo backed by a 4L80E. Research has gotten me to just about all I will need:

1. Engine mounting Edelbrock #6701 adapters
2. Headers Edelbrock #67073
3. Electronics Speartech
4. Fuel Pressure Regulator Corvette filter-regulator
5. Fuel pump not to sure yet who to use but that is a small issue, still working out how to baffle the tank. Im not going to buy one of those aftermarket tanks at 800.

Does anyone with insight see anything that I have missed or need to address before I start purchasing parts? Give me all the pit falls anyone has gone through in swaps or if the LS3 has any quirks.

Apr 25, 2008 | 12:49 PM

garys 68

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From: Camdenton, MO

Last I saw GM made a plug and play harness just for the LS3. It included the drive by wire accelerator assembly, computer, harness, etc and was cheaper than most of the aftermarket. Look up PN 19201861

Apr 25, 2008 | 02:35 PM

poorhousenext

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From: TN

Quote:

Originally Posted by 406 Q-ship

Which crate LS3, 430HP or 480HP?

Apr 26, 2008 | 07:54 PM

Project GatTagO

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From: Little Austin

Quote:

Originally Posted by garys 68

That harness is manual trans only. I would get with John at Speartech on an ECU/harness combo that will control your 4L80E as well. An alternative is to run a programmable ECU for the transmission and get a paddle shifter:

http://www.twistmachine.com

Andrew

Apr 26, 2008 | 08:55 PM

john 67

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From: New York City

i agree ,you need a harness that will control both engine and trans speartech will be doing mine soon.JOHN

Apr 27, 2008 | 01:56 AM

406 Q-ship

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I will use the SpearTech because I want the trans to be controlled by the engine PCM. There is only one LS3 the 430 horse the 480 is a cammed and carbed LS2

Apr 27, 2008 | 11:41 AM

subtlez28

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From: Janesville WI

Quote:

Originally Posted by 406 Q-ship

I will use the SpearTech because I want the trans to be controlled by the engine PCM. There is only one LS3 the 430 horse the 480 is a cammed and carbed LS2

Not true. GMPP makes a "LS376/480". It is the LS3 crate engine w the "hot cam". It is fuel injected. Pages 114 and 115 GMPP 2008 catalog.

They (are going to) make a stand alone harness for this, though I've read (on here) it isn't released yet.

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Apr 27, 2008 | 05:10 PM

poorhousenext

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From: TN

Quote:

Originally Posted by 406 Q-ship

I will use the SpearTech because I want the trans to be controlled by the engine PCM. There is only one LS3 the 430 horse the 480 is a cammed and carbed LS2

It's my normal pratice to never post what I don't know to be fact. I've had a LS3 480HP crate engine in my hands since middle of March when they came off BO I placed in Feb when part number went active in GM dealers computers.

I was still #26 on BO list. Just in case you want a 515 HP LS3, GM offers a carb version listed with that HP also.

Engine Overview: LS 376/480
LS3 + Hot Cam = Loads of Fun.

What's Hot?

· Hot Cam!
· Big EFI power
· 24-month GMPP warranty

The hot new small block V8 in the GM lineup is the hyper-aggressive LS3. It offers a high-revving 376-inch combination that represents generations of small block V8 development and engineering. Not only is the LS3 an amazing engine in its stock configuration, but with those high-flowing rectangular port cylinder heads, the LS3 is loaded with potential. To tap into this potential, the engineers at GM Performance Parts offer you the LS 376/480 – an LS3 with an upgraded camshaft that ups power by a whopping 50 horsepower!
The LS 376/480 comes with the same great features as the LS3 crate engine. The bottom end includes a 6-bolt aluminum block, nodular crank, high performance rods, and 10.7:1 pistons. The heads are high-flowing rectangular-port units that share their design with the amazing LS7. The same EFI intake manifold feeds the hungry engine, while 1.7:1 roller rockers work with the upgraded camshaft.
The GM Performance Parts engineers picked the LS Hot Cam (p/n 12617570) to take the LS3 to the next level. This cam specs out with .525-inch intake and exhaust valve lift. Duration (@ .050 inches) is 219° intake and 228° exhaust. This cam allows for a dramatic increase in power across the power band while still maintaining good street manners. The engine will idle and cruise just like an LS3, but the power increase is there whenever you need it.
With all of the same great components as the LS3, but with an additional 50 horsepower, the new LS 376/480 is ready, willing, and able to answer your call for a new LS crate engine.

Engine Overview: LS 376/515

What's Hot?

The LS3 gets a big cam and carbureted intake manifold for an additional 120 horsepower!

· Bigger Cam!
· Carbed intake
· 24-month GMPP warranty

You know that the LS3 is the hot new small block V8 in the GM arsenal, but you still want more. We proudly offer you the LS 376/515, an upgraded LS3 that is equipped with an aggressive camshaft and GM Performance Part's exclusive carbureted intake manifold. Two simple upgrades that add up to 515 horsepower – a 115 horsepower bump over the stock LS3.
To match the high flow rate of the LS3 cylinder heads, our GM Performance Parts engineers installed the "ASA Hot Cam" (p/n 12480110). This is a hydraulic roller camshaft that offers up .525-inch intake and exhaust valve lift numbers and duration @ .05-inch of 226° intake and 236° exhaust. It truly is a "hot cam" that offers up an aggressive lope at idle and a buzz saw power band that never stops.
The GM Performance Part engineers coupled that aggressive camshaft and high flowing cylinder head design with our new carbureted intake manifold specific for the L92/LS3 cylinder heads (p/n 25534401). The manifold offers a dramatic increase in horsepower and a simplified installation.
If you like what you see with the new LS3, you'll love the LS 376/515. It's everything you want in a small block V8 – big power, simple package, and a big-inch foundation. The GM Performance Parts intake allows for an easy installation that you will find familiar while still being very powerful. The LS 376/515 – the next great small block from GM Performance Parts.