what happened to Swingers in 1973?

I have a 73 Swinger (318). I have a few questions about 73s that might be easy for a lot of y'all.

-it has the "new" 5 mph bumpers in front. In back too?

-was a 340 made in the Swinger model in 73 or was it just available in a Demon?

-I thought it would be easy to find but I haven't found the horsepower of a stock 318...anybody know it or where to look?

Thanks.
Mr. Charlie