.050 over 292 pistons and EBU rods. .050 over 292 is standard bore 312. the story goes my 292 short block was rebuilt in 1967 but never run. it sat on a shelf in a dry and heated shop. the only reason i'm not running them is i decided to go with a 4-71 blower and wanted better rods and forged low compression custom blower pistons. i want $100.00 plus shipping.