Engine casting numbers are generally on the rear of the block behind the heads. There are lots of places on the internet with casting number info.

http://www.nastyz28.com/sbchevy/sblock.php

http://www.ajgeneral.com/bbc_block_casting_numbers/

http://www.nastyz28.com/bbcmenu.php

Those are just a few.

The glass is twice as big as it needs to be.