Oldsmobile used a 230 six from 1937-1940, I believe.
Here is a nice pic of the 37' Olds 230. There is more info on the engine in this
37' brochure if this is your engine.
http://www.oldcarbrochures.com/main.php?g2_itemId=60603

1/2 ton 1937 GMC pickup also used the Olds 230 six.
http://auto.howstuffworks.com/1937-gmc-pickup.htm


"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson