ACSD - Blanking plate part number

[fake name]

For a 50 cent o ring, its a no brainer. The existing o ring is probably 25 -30 years old. Possibly a pre viton material

that makes perfect sense. But, there seems to be two possible o-rings for for our engines. So, for some UNKNOWN reason, my brain tells me to buy the correct one before starting the project. But, when you say it like that…”it’s only a 50¢ part”…I now realize…it’s only a 50¢ part So…I’ll just buy them both

 

[fake name]

So…does anyone know the ID size of coolant line?

 

[roscoFJ73]

But, there seems to be two possible o-rings for for our engines.

Are they different in size or shape.

• How to Properly Size an O-Ring The First Time Around. They even have a phone app that sizes o rings!

globaloring.com

 

[HDJ80L]

Got this from my local dealer (~ 13$), appears to be similar/same as the Denso timer cover.
Not sure if you can source it through NA dealerships though.