I am building a 402ci using a 6.0 iron block topped with L92 heads. I purchased stock GM head gaskets for a 6.0. I noticed this:

Front:


Rear:


I made sure the gaskets were front to front. Someone please tell me this is normal as I have already torqued the factory GM bolts!

 

Anyone?

 

Seriously nobody? Maybe it is a stupid question but I would rather ask and not have a mistake on my hands.

 

I have a 6.2L on a stand right now and I just checked it and its similar. I have about 1/10th of that hole exposed on the rear only and oddly enough only on one head. This engines heads have never been off from the factory so Id say your good

 

Great. A big thanks to you!

 

John, got your email and responded! Nothing to worry about there! That's perfectly normal!

 

Thanks Matt! Once again, Texas Speed showing value added service from their organization.

 

I'd not be so sure... the picture you showed is not a problem, everyone is correct about that. What I would worry about is the bore size of the gasket. The LS3/L92 heads normally have a chamber that is larger than the bore diameter of the 6.0 head gasket. I would check your heads to verify that the gasket is not protruding into the chamber (bad)... This could lead to a blown head gasket.

Shane

 

12610046 is the part number you need. Good call, Shane.

 

I really think I am okay with the 6.0 head gaskets based on GM’s specifications on the heads. It says they will fit 4.00” or larger bore. It doesn’t make any sense to me that the chamber width would be greater than 4.00 inches.

12615355
L92 Cylinder Head Assembly
• Aluminum performance head
• Fits any LS family engine with 4.00" bore or larger
• 2.165" solid stem intake, and 1.59" solid stem exhaust valves
• .510" max valve lift
• As-cast L92 style intake ports
• D-shaped exhaust ports
• As-cast combustion chambers

My bore is 4.005” and my head gaskets are 4.02” per the GM catalog. My heads are already torqued down and I really don’t want to pull them to measure the chambers and trash my OEM head bolts. Does anyone have an L92/LS3 head off motor to take a quick measurement? If indeed the chamber is no more than 4.00”, it doesn’t seem that the L92 head gaskets (4.080”) are the right choice on a stock bore 6.0L. That extra .080” would collect a fair amount of carbon I would imagine.

Matt?

 

The part number I posted above works on 6.0L and 6.2L applications. Do you know which part number you purchased?

 

Hey Matt. Here is what I used:

12589227
LS2, L76 Head Gasket

 

No bueno! That gasket measured right about 4.040" or so in diameter. Your cylinder heads measure a good bit larger than that, which will be problematic

 

Well crap! I'm going out to pull them off now. Looks like I will be giving you a call to place an order.

 

Dang lucky thing you didnt follow my shade tree advice

Mind you its best to run into this now while your working on it then after its all up and running that would have been a MAJOR pitfa. **** happens and I would chalk this up to a small shart rather than a full on ***** yourself type problem.

 

Your advice wasn't wrong as we were only talking about the corners of the gaskets at that time. Many people said that was normal. You are right it is good to catch it now rather than later. I have always been taught that what appears to be a dumb questions is better than a dumb mistake.

I pulled one of my heads and did a measurement. It confirms what Matt from TS said. My chambers measures 4.075" - 4.080". So for anybody putting the L92 heads on a 6.0 block, use L92 head gaskets! And shame on me for not noticing the problem during assembly.

Once again, thanks to Shane, Matt and thiis LS1 forum!

 

I'm glad I could help.

Shane