Don't know if there's much more we can tell you. As you correctly surmised, the casting number is that of a 1968, 327 2 bolt.

The other numbers are partial VIN, however 7193214 does not follow Chevy sequencing conventions, as you've probably already determined.

The "TO618" tells me that the block is from Tonawanda made on June 18th. The "1HH" does not match anything in 1968. This could be a replacement engine with some of the numbers stamped by a local dealer.

What additional information would be helpful? If you're going to build it, you already know what size it is and it appears to have been bored and ready to final hone for .030 over.

You have several crank options (some of which may require machine work for clearances).

302 = 4.000" x 3.00" (5.7" rod)
327 = 4.000" x 3.25" (5.7" rod)
350 = 4.000" x 3.48" (5.7" rod)
350 = 4.000" x 3.48" (5.7" rod)
383 = 4.000" x 3.80" (5.7" rod)


Regards,
Glenn