I think I finally found a 235 for my project, but the seller isn't sure enough to ask me to make the drive without verifying the casting number, which I haven't found anywhere on the web.
The passenger side, rear of the block has "2775308" and "0.30.74" and a casting clock (pointing up).
Anybody have any good references? I'm hoping this isn't a 230 (it came out of a '62, unless it was a '64).