1978 Mercruise 165 Expansion plugs, size?

[Barefutn]

I am working on a Mercruiser 165 and the expansion plugs were removed. I've tried 7/8" and that's too large. 3'4" is too small. I'm in California and bought the boat out of Montana. The freeze plugs were toast when it arrived. Does anyone know what size and where I might find them. The host boat is a 1978 Monark law enforcement version with enclosed wheelhouse.

 

[Bondo]

I am working on a Mercruiser 165 and the expansion plugs were removed. I've tried 7/8" and that's too large. 3'4" is too small. I'm in California and bought the boat out of Montana. The freeze plugs were toast when it arrived. Does anyone know what size and where I might find them. The host boat is a 1978 Monark law enforcement version with enclosed wheelhouse.

Ayuh,..... Welcome Aboard,..... Must be 13/16" as that's what's 'tween 3/4", 'n 7/8",....

Btw,..... They're Core Plugs, that pop out when the motor freezes with water in it,...

Is this a Merc 165, 4 cylinder, or a Merc 165, 6 cylinder,..??

 

[Barefutn]

Hey Bondo. Thanks for the response and the welcome. It's a 6 cylinder. I ordered the core plugs at 13/16ths and they sent out 7/8". Now I can't seem to find the 13/16" available. I'll put in a call to Dorman and see if they can locate them. I'll keep grinding. Thanks again, Rob