yea i know but the subject was there....

 

Are they Chevy 355's or Olds 355's? Neither company made a 355 size engine. They're both derived from having their cylinders bored .030" over. Chevy 350 4.000" bore to 4.030" bore. Olds 350 Rocket 4.057" bore to 4.087" bore.

Finding 5 Olds 350 that were bored .030" are probable from someone that used them for racing. Probably some type of circle track racing. We used to have a guy around here that used Olds 350 motors for dirt track racing in a stock engine type class. He did pretty good.