The "domed" pistons were used in the late 1930's-early 40's engines, weren't they? They've got a slight radius on top, not a huge lump like most folks associate with a racing piston. I've seen lots of NOS domed pistons on ebay auctions and they're always listed as early 216 applications.
Jerry
Edit: There are several sets of 1937-1940 domed new old stock pistons on ebay now, in various oversizes. 1941-up pistons are flat tops.
Jerry
Last edited by Hotrod Lincoln; 11/22/2013 8:57 PM.