I have a 81 El Camino and I blew a head gasket so we decided to just drop in a new motor so I went ahead and got a new 350 bored 40 and so but anyway when we pulled the old motor and i cleaned the transmission i saw it had a large M with a small line under it I was just wondering if anyone knew what the underlined M stood for what is the meaning of it ? Thanks for any help

 

Hi bigjab22,

Welcome to the Chevy Forums.

That is the letter designation for where the engine was built.

In this case, most likely it was a crate engine from GM of Mexico.