340 Piston identification. Silvolite?

Strange markings and oh..the badger #is p296 and P294, still weird with the SL

Here's some info

These are part numbers from www.nhra.com
http://www.nhra.com/tech_specs/pistons/
Stock pistons that are accepted by NHRA in Stock Eliminator.
68-71 CHRYSLER 275-290HP 340 10.5:1
L2316F TRW
2332P SEALED POWER
P1610 CHILDS & ALBERT
275-340 VENOLIA
B284 BADGER
JE 136627
55328 ROSS

72-73 CHRYSLER 240HP 340 8.5:1
L3062F TRW
2369P SEALED POWER
P296 BADGER
L2385F TRW
240-340 VENOLIA
148623 JE
99588 ROSS
CP Pistons M5-CP