[leejoy]

when choosing head gaskets you need to know the bore size. I've got a 454 which is a 4.250 bore. It's bored .060 over so that 4.310 bore size.

my question is: when choosing a head gasket, what bore size do I want for the gasket? Do I choose a 4.310 bore or do I go bigger than that to like a 4.370"

thanks

Lee

[dgcantrellsr]

Originally Posted by leejoy

when choosing head gaskets you need to know the bore size. I've got a 454 which is a 4.250 bore. It's bored .060 over so that 4.310 bore size.

my question is: when choosing a head gasket, what bore size do I want for the gasket? Do I choose a 4.310 bore or do I go bigger than that to like a 4.370"

thanks

Lee

You can use the one for the 4.310 bore. Stock gaskets will accept .060 over.

[F-BIRD'88]

The actual bore size of a cylinder head gasket is always larger than the engines cylinder bore size. Most 427/454 BBC head gaskets are 4.37" or larger.
You cannot accurately calculate an engines compression ratio without knowing the head gasket bore size and compressed thickness or the actual compressed volume.
If you want to get a little more compression ratio on a 454 by using a thinner head gasket, get a 1970 Chevelle 454/450hp LS-6 steel shim gasket from a GM parts dealer.
Works fine al long as the block deck has not been cut a whole lot.
Need a total block/piston clearance of .040" or more, including the gasket.

It is only .022" thick as compared to a typical felpro at .039" to .041"