Plastic clots cylinder block

These ones in the base of the block do nothing to help dampen fin vibration.
To reduce fin ringing they would need to be inserted between the fins.
These ones are only plugs which serve to prevent muck building up in the holes which could drop in to the crankcase when lifting the barrels as they are close to the mouth of the cylinders.
The holes were originally used to locate the blocks on a fixture at the factory for machining operations.
From a mechanical point of view you can leave them out, leave them as is or bung the holes with something else.

zed1015 wrote: These ones in the base of the block do nothing to help dampen fin vibration.
To reduce fin ringing they would need to be inserted between the fins.
These ones are only plugs which serve to prevent muck building up in the holes which could drop in to the crankcase when lifting the barrels as they are close to the mouth of the cylinders.
The holes were originally used to locate the blocks on a fixture at the factory for machining operations.
From a mechanical point of view you can leave them out, leave them as is or bung the holes with something else.

Thank you for advise, in other word, I don`t do anything and just leave the existing plugs in the whole ?

Yes! Just leave them in.

zed1015 wrote: These ones in the base of the block do nothing to help dampen fin vibration.
To reduce fin ringing they would need to be inserted between the fins.
These ones are only plugs which serve to prevent muck building up in the holes which could drop in to the crankcase when lifting the barrels as they are close to the mouth of the cylinders.
The holes were originally used to locate the blocks on a fixture at the factory for machining operations.
From a mechanical point of view you can leave them out, leave them as is or bung the holes with something else.

Ya learn something every day on here!