Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

How to externally identify a 5.7 LS1???

Thread Tools
 
Search this Thread
 
Old Dec 8, 2010 | 02:10 PM
  #1  
SpeedFreak350's Avatar
Thread Starter
Teching In
 
Joined: Dec 2010
Posts: 2
Likes: 0
Question How to externally identify a 5.7 LS1???

I'm going to be picking up an 5.7 LS1 engine. Question is, how do you differentiate between the LS engine varieties? Don't they all look alike? I don't want to end up with a 4.3 or 5.3... Any markings to look for? I know I could take the seller's word for it, but I have trust issues Thanks!
Reply
Old Dec 8, 2010 | 02:34 PM
  #2  
NVR_SPDS's Avatar
TECH Addict
iTrader: (39)
 
Joined: Aug 2003
Posts: 2,129
Likes: 3
From: Virginia
Default

Back passenger side of the block says displacement. You should also be able to use the casting number just below the drivers side head, on the back of the block. Check head casting numbers too.
Reply
Old Dec 8, 2010 | 03:44 PM
  #3  
Always2Slow's Avatar
TECH Enthusiast
iTrader: (8)
 
Joined: Apr 2006
Posts: 639
Likes: 1
Default

Just make sure its aluminum. Only the LS motors are aluminum and truck motors are cast iron.
Reply
Old Dec 8, 2010 | 03:52 PM
  #4  
NC98Z's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Sep 2003
Posts: 1,306
Likes: 0
Default

4.3 is a six cylinder and a 5.3 has a cast iron block.
Reply
Old Dec 8, 2010 | 03:59 PM
  #5  
Anniversary "Z"'s Avatar
12 Second Club
iTrader: (26)
 
Joined: Sep 2004
Posts: 680
Likes: 0
From: Liberty, MO
Default

Originally Posted by NVR_SPDS
Back passenger side of the block says displacement. You should also be able to use the casting number just below the drivers side head, on the back of the block. Check head casting numbers too.
^^ what he said, kinda hard to pass these blocks off for something they are not since GM stamped "5.3, 5.7, or 6.0" into the mold these blocks came from
Reply
Old Dec 8, 2010 | 04:17 PM
  #6  
SpeedFreak350's Avatar
Thread Starter
Teching In
 
Joined: Dec 2010
Posts: 2
Likes: 0
Default

Cool, thanks everyone! I'm searching for the casting #s right now.

Last edited by SpeedFreak350; Dec 8, 2010 at 04:24 PM.
Reply
Old Dec 8, 2010 | 07:37 PM
  #7  
Mighty Whitey's Avatar
12 Second Club
 
Joined: Feb 2006
Posts: 876
Likes: 0
From: Catlettsburg, Ky
Default

The only instance you need to worry about the casting # to identify displacement is when purchasing a cast iron 5.3, they share the same block as a 4.8. Other than that, all the displacement numbers are cast in the block
Reply
Old Dec 8, 2010 | 08:02 PM
  #8  
BStowers023's Avatar
Launching!
iTrader: (1)
 
Joined: Sep 2009
Posts: 227
Likes: 0
From: Gulfport, MS / Columbus, OH
Default

853 and 241 are stock casting LS1 head numbers.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

10 Reasons Daily Driving a Swap Project SUCKS! (& 1 Reason to Do It Anyway)

 Michael S. Palmer
story-1

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-2

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-3

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-4

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-5

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-6

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-7

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-8

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-9

Top 10 Most Powerful Chevy Trucks Ever Made!

 
Old Dec 8, 2010 | 09:04 PM
  #9  
NVR_SPDS's Avatar
TECH Addict
iTrader: (39)
 
Joined: Aug 2003
Posts: 2,129
Likes: 3
From: Virginia
Default

Heres a reference for casting numbers:
http://chevythunder.com/LS1%20components.htm
Reply




All times are GMT -5. The time now is 08:07 PM.

story-0
10 Reasons Daily Driving a Swap Project SUCKS! (& 1 Reason to Do It Anyway)

Slideshow: 10 reasons daily-driving a swap project might not be for you. Or is it?

By Michael S. Palmer | 2026-06-17 09:39:05


VIEW MORE
story-1
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-2
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-06-18 10:26:23


VIEW MORE
story-3
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-4
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-5
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-6
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-7
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-8
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-9
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE