I want to buy thin head gaskets to raise compression and set quench. The lowest price I see on Cometic .040 is $150 a pair. FelPro 1041 are only a little cheaper. Speedmaster .040 MLS are $50.00 but..... they're Speedmaster.
Then I found these: 519974
http://scegaskets.com/product/pro-se...-chevrolet-ls/.
I'm on a very tight budget and these are $52 a pair. .041 thickness Made in USA. The bore is a bit on the large side but not as bad as the FelPro. Graphite would be harder to clean up if I ever had to replace them. I may have to re-torque after the first heat cycle. Still, they should get the job done reliably and the price is right.
Has anyone heard of SCE ? Has anyone used these particular head gaskets ?

 

Honestly, I like the fel-pro very much. I don't know what heads you have, but if they have that notch near the middle cylinders on the deck surface, the fel-pro MLS is the only one that I know for sure will seal. It has a relief cut out specifically to allow for that notch. There was a version of the fel-pro with a smaller bore that I found and used.

Never heard of SCE

 

I have 243
These have that notch also but it says they will work for LS6. (2)1997-2001 Gen 3 engines with GM head castings; 5339, 8806, 9862 must use this composite head gasket to prevent coolant leaks on lower side of cylinder head.
I guess I'll be the guinea pig.
BTW, I really appreciated your help in my, "Help me Understand Valve Events" thread.

 

My thoughts are that matching the bore diameter is more important than tightening the quench. Having a .036" ledge around the bore top is still terrible for emissions and BSFC numbers. Your trading bore matching .045 quench (GM MLS) for shitty crappy gasket bore ledge (dead combustion) and .034" quench.....
They are great gaskets quality wise but IMO only the shear cost reduction is a good thing for your particular application

 

My pleasure. Just paying forward what I've learned on here when I can. I didn't realize any 243's had the notch. I thought it was restricted to the 806, 862, 853, and some 241

 

Did some digging around, and I'm seeing this:

1. Cometic has bores of 3.910 and 3.970 showing as OK for the LS1, with the 3.970 showing as the recommended head gasket, though I'm sure a lot of guys are running the 3.910 without issue.

2. Fel Pro has 3.945 and 4.060 showing for the LS1 along with other sizes

3. SCE that you linked above has 3.970" bore. Looks like they would seal just fine, though

 

Yea 3.970 "fire ring". Sounds like a circus trick. I wonder if that's compressed or as-shipped. I read the install pdf and it said the ring was stainless, there to protect the graphite. I will get a good measure when they get here, I bought them today.
My 243 has no notch, I think they were saying the gasket could work on both. The add copy is not good and the phone staff not that knowledgeable on this product. SCE's thing is their copper gaskets, I guess.
What is BSFC ?

 

Brake Specific Fuel Consumption
The measure of an engine's efficiency or more accurately:
The number of pounds (lbs.) of fuel Per/hour needed to support each horsepower the engine makes.
Engineers are always trying to get more power out of less fuel.
Think of it this way.....as technology allows engines to make maximum power from less degrees of timing advance; i.e. the flame propagation is faster so the engines BSFC number goes down.
Old sixties crap had domed pistons with inefficient combustion chambers, crappy ignition systems and leaded gas which is dirty and slows the flame speed. They often needed 42-44 degrees of lead to run well.
70s and eighties stuff developed better ignition systems, head runners, chambers and often flat tops or dished as the gas quality suffered but 36-38 became the all too often sweet spot. Late nineties vortec truck stuff which was a lot like LT runner/chamber stuff usually only needs 32-34 degrees and will not lose much if any power as low as 29-30 advance.
Now LS stuff comes about 22 from the factory and plenty of tuners only go 24-28 range which shows how much better the Sperry Brothers head design truly is.

 

I've used SCE before. Never on a ls1 however. No issues on two sbf engines, one was 13.5:1 the other was 11.1:1. Never sprayed either so idk how they might hold up with fi.