I did not know that about the mains. I knew about the line boring but didn't know why since that is usually not an issue with later GM sixes. The 216 in my $55 '48 Fleetline made me an Inline guy. Dad & I removed some shims but a tear or so later when it finally let go I had access to a fresh 235. Thanks for the information. I'm staying tuned to follow this.

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain