LS3 head gaskets

Reply Subscribe

Thread Tools

Search this Thread

Jul 16, 2009 | 10:45 AM

marksboy7

Thread Starter

On The Tree

iTrader: (6)

Joined: Jun 2007

Posts: 197

Likes: 0

From: Leoma, TN

LS3 head gaskets

What gaskets are everyone using on ls3's? The closest gasket i've seen is the stock ls3 gaskets that say they can take up to a 4.080 bore. Are there any thinner gaskets for a 4.070 bore than 0.051? How close does the gasket need to be to the actual bore size?

Jul 17, 2009 | 07:24 PM

RPOWU8

11 Second Club

iTrader: (13)

Joined: Dec 2001

Posts: 145

Likes: 0

From: Escondido, CA

I've built an LS3 crate motor for my camaro. The LS3 gaskets measured 4.100 diameter and they are supposed to be .054 thick.. The stock LS3pistons were out of the block by .010.

I ended up using LS7 Gaskets on my LS3. They were 4.160 Dia and are .051 thick. My heads have had the chambers CNC'd and the LS3 gasket was a little smaller than the chambers. I did not want the gasket sticking out into the chamber. If the chambers are stock I would stick wih the LS3 gaskets. Make sure you have at least .035 quench clearance.

Dee Jay

Jul 18, 2009 | 03:08 PM

LS1MCSS

TECH Junkie

iTrader: (18)

Joined: Jan 2006

Posts: 3,831

Likes: 8

From: Dover, Arkansas

I got 4.085 Cometics .051 thick for my engine. I am pretty sure I got them from TSP.

Jul 18, 2009 | 08:24 PM

71CamaroLS1

Launching!

Joined: Dec 2003

Posts: 251

Likes: 2

From: Portland OR

I'm using Cometics at 4.085 bore, .036 thickness on my LS3 crate motor, for more compression and better quench (.036 is what I'd consider bare minimum thickness). Some people have complained about coolant leakage issues with Cometics on LS7s, but I've used them for 1000s of miles on both an LS1 and LS3, street and HPDE, without any problems.