A friend and I are looking at building an engine from spare parts. We are looking at a Gen 6 standard 502 block that is currently a 565. The bore is 4.535 and the stroke is 4.375. We don't know the condition of the block yet but we were wondering if it needs to be bored out what would be the next bore level (4.56)? This is not a Bowtie block. I have also read some old forum posts and some say you can't and some say can go all the way out to a 4.6 bore. I am sure either way we will have to get it sonic checked.