I am buying an Lt1 block rods and crank Wed. For a 355 build,most on here agree that 060 is too large but how about 040,thats what i did with my mustang -stock internals ,LE1 econo port&cam,just a little better than stock maybe 320 to the wheels NO SPRAY ever just a fun little motor

 

much easier to get pistons for .030 over

 

You need to have the block sonic tested, I have found LT1 blocks that I would be worried going .030" over due to super thin cylinder walls.