Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

LM7 W/LS1 Heads

Thread Tools
 
Search this Thread
 
Old Sep 28, 2010 | 11:37 PM
  #1  
hcb1700's Avatar
Thread Starter
TECH Regular
15 Year Member
Photogenic
iTrader: (9)
 
Joined: Oct 2007
Posts: 446
Likes: 1
From: Oakland, California
Default LM7 W/LS1 Heads

I just want to know if it would be worth swapping the stock LM7('00) heads for some LS1('01) heads since they have bigger valves? My brother did a heads and cam swap on his Z28 and these parts are just laying there. Would they work/fit without any problems? Don't the LS1 heads have smaller combustion chambers, therefore giving a slightly higher compression ratio? I'm looking into swapping this engine into my '78 Z28 and need to know this before I drop it in.
Reply
Old Sep 29, 2010 | 09:38 AM
  #2  
chevyboy91188's Avatar
Launching!
iTrader: (15)
 
Joined: Jul 2010
Posts: 236
Likes: 1
From: Tampa, FL
Default

Ls1 has bigger chambers, don't know where you heard they are smaller? Think about this, ls1 is a bigger engine and compression ratio is what? Like 10.5 to 1, the 5.3 is smaller and its cr is 9.5 to 1 those are pretty close especially considering the ls1 has flat tops and the 5.3 dished pistons. The heads almost flow the same too. A common upgrade on ls1 is getting 5.3 ported and have bigger valves put in them. Really no one wants ls1 heads unless they have the l33 like me which has 9.9 cr due to flat tops in this model, and I would only need them to lower my cr so I could use forced induction.
Reply
Old Sep 30, 2010 | 02:48 PM
  #3  
deuce4935's Avatar
TECH Resident
15 Year Member
iTrader: (2)
 
Joined: Sep 2006
Posts: 760
Likes: 3
Default

What I did was took the ls1 valves and installed them on the 5.3 heads, had them ported and polished along with a spring upgrade.
Reply
Old Sep 30, 2010 | 09:46 PM
  #4  
hcb1700's Avatar
Thread Starter
TECH Regular
15 Year Member
Photogenic
iTrader: (9)
 
Joined: Oct 2007
Posts: 446
Likes: 1
From: Oakland, California
Default

Originally Posted by deuce4935
What I did was took the ls1 valves and installed them on the 5.3 heads, had them ported and polished along with a spring upgrade.
What cam are you running?
Reply
Old Oct 1, 2010 | 09:55 AM
  #5  
deuce4935's Avatar
TECH Resident
15 Year Member
iTrader: (2)
 
Joined: Sep 2006
Posts: 760
Likes: 3
Default

A Comp custom grind with low .600" lift.
Reply




All times are GMT -5. The time now is 09:14 PM.

story-0
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-1
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-2
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-3
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-4
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
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE