Perfect Circle # TC-1737. There's a set on Ebay right now, .040" oversize.

https://www.ebay.com/itm/185155177277?

Silv-O-Lite # 1438:

https://www.ebay.com/itm/331741811966?

Even the ones with the chamfer, like Speed-Pro, Sealed Power, and similar ones, give a compression boost over the dish top 250 pistons. Sealed Power and Speed Pro offer hypereutectic alloy, which is much stronger than regular cast piston material, and half the price or less of forged. I've CC checked several sets of both designs. There is a big difference between information that gets repeated on various websites about a rumor "I heard somewhere" and facts presented by someone who has "been there- - - -done that". Guess which category I fit into? I built my first flattop piston 250 in 1985.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!