Help Identifying a part Mercruiser 3.0 off 2003 bayliner

[MPIERCE9]

I have these parts from a partially assembled engine and i'm not sure what they are for or where they go. Was looking for some help. They each have a small hole through the piece.
Engine Serial Number M379464 - Mercruiser (3.0l / Lx Alpha One Engine) Engine Components

 

[alldodge]

No clue, may have been plugs used to keep dirt out prior to assembly

 

[GA_Boater]

What are they made of?

 

[Bondo]

Ayuh,..... Welcome Aboard,...... My guess is, they're screw caps lost off a lawn chair,.....

 

[MPIERCE9]

What are they made of?

Made of what feels like a hard plastic or light metal. They are not magnetic.

 

[MPIERCE9]

Made of what feels like a hard plastic or light metal. They are not magnetic.

Correction, these are made of steel.

 

[QBhoy]

They ain’t off the engine

 

[Scott Danforth]

Welsh plugs for the anti-tamper on the idle mix screws