factory 72 340 pistons???

Early 340 pistons had 2 valve reliefs and stuck a little above the deck. 72-73 had flat tops with 4 valve reliefs that were .080 below the deck or so. Those pistons pictured are aftermarket. Measure and see if they come close to deck level or stick way below deck. They look like some pistons I put in one of my 340s. About 9.5:1 w open chambered heads or closer to 10:1 with some closed chambered heads.