This is a factory 454 block .030 that was machined by another shop. I have seen work from this shop many times and their work has always been spot on. This is a marine build went to plate hone the block and measured the cylinders they were .0035 distorted. I can not stress enough that on factory blocks plating honing is a must to achieve good ring seal. People say the rings will break in LOL I have seen circle track engines with rags around the breathers for 2 or 3 years leak them down up to 35% leak down. I have always said its best to do a leak down 40 to 50 degrees BTDC or after TDC. Here is an article I did on plate honing years ago https://www.chevelles.com/forums/148...rlhkkkWTSDDaDo
Years ago some really sharp machinists who did a lot of machine work for a fist full of NHRA stock guys insisted on the use of a torque plate (and all kinds of funky stuff with those stock guys like running 180 degree water through the block as it was being bored and honed). If I had the $$ I would get one for my 6 motors.