340 head gaskets

[RoRo7051]

Hey yall.

I'm replacing the head gaskets on my 340.

I noticed that some ports in the block are covered by the gaskets. Others have an opening which is much smaller than the port I'm the block. Is this normal? Do I need to modify the gasket in anyway? Example photos added for reference. You can see that at the bottom right of cylinder 1, there are two ports on the block, only 1 opening in the gasket. On the bottom left of cylinder 1, the opening in the gasket is much smaller.

Thanks much.

 

[tinman2]

 

[toolmanmike]

Hey yall.

I'm replacing the head gaskets on my 340.

I noticed that some ports in the block are covered by the gaskets. Others have an opening which is much smaller than the port I'm the block. Is this normal? Do I need to modify the gasket in anyway? Example photos added for reference. You can see that at the bottom right of cylinder 1, there are two ports on the block, only 1 opening in the gasket. On the bottom left of cylinder 1, the opening in the gasket is much smaller.

Thanks much.

View attachment 1716068948

View attachment 1716068949

Some holes need to be open and some don't. The head gaskets are the same for the left or right bank so some holes you see are functional and some are not.

 

[Bewy]

The holes in the heads/block are coring holes. The 'holes' that are actually sized & regulate coolant flow are the head gasket holes.