I post this as a question and a response. We run a 413 block in our '63 N/SS Plymouth. It's bored .060 to make it 426". It is an industrial block with the extra webbing on the sides. Otherwise it's been built as a race engine from back in the day...12.2:1, Max Wedge heads and intake, two Carter 750's, and a big roller cam. The car runs in the 10.90 range.

That being said, my father and I got into a discussion just yesterday when I told someone that our engine was a 413 + .060. He said, "No, it's a 426!" If I remember correctly, weren't the '62 and early '63 cars 413's? I believe in mid '63 they went to 426". My question is, was the 426 a new casting, or were they 413's that were over-bored? Thank you in advance.