What year did the LA 318 come out?

On a side note, an old friend "back in the day" had a junk Dodge, I needed a temporary engine. This was about ?? 1977 or so. He thought it was a 318, sold the greasy mess to me for 50 bucks, and it turned out to be a 273 LOL. Dumped it into the 70 RR while I was reworking the 340. Amazing for no more than "what it was"