Head gasket bore size vs cylinder bore size.

[pocket-rocket]

Why is the stock head gasket hole so much bigger than the one in the block (and these new gaskets)? Why can't they be closer in size (say more than the .020 gectek quoted). It just seems to me getting them closer to the same bore size would help out a little on the compression and quench side of things.

[SappySE107]

The MLS gaskets can be any bore.

[pocket-rocket]

I realize this, I'm just wondering what the reasoning behind GM making stock ones so large from an engine builder stand point. I know one reason is for the same gasket despite overbore, but if stock is .130 and max overbore is .060, why the more than 2x larger bore size? Lower quench/compression for emissions?

[gectek]

Gm has their own reasoning for alot of things. easy to explain, not one of them. Usually they will have something in mind for service limits or compatibility between one engine/vehicle to another. supposed they make the 3400 here, but they make a 3500 somewhere else, or 3600 of the same stroke but bigger bore. they can save money by using only one part for service head gaskets. easy enough?

[gectek]

GM doesnt build engines. Lol. They do not engineer every aspect of a car either.

[pocket-rocket]

Usually they will have something in mind for service limits or compatibility between one engine/vehicle to another. supposed they make the 3400 here, but they make a 3500 somewhere else, or 3600 of the same stroke but bigger bore. they can save money by using only one part for service head gaskets. easy enough?

That I can buy into (one gasket for multiple engines). Thank you guys for putting up with my n00bness.

[SappySE107]

1 part, any overbore. Asking why GM does something is a toss up between bean counters, longevity, compatibility, emissions, and on 60V6s, rarely performance.

[pocket-rocket]

1 part, any overbore. Asking why GM does something is a toss up between bean counters, longevity, compatibility, emissions, and on 60V6s, rarely performance.

True dat, dog...

Thanks again guys