Where do I find this on my engine and later use those numbers to identify it on a GM casting list of some sort .....My engines BBC 572's

Block casting number should be on the back were the bellhousing bolts up

http://www.mortec.com/bbc.htm

Noticed there are no casting numbers "listed" for bbc engines that are larger than the 502 cu.in.
Is that an incomplete list?.......or...... is the 502 engine a platform for all larger bored engines?....such as a 572

A 572 is a bored and stroked 502. Bore is 4.56 and stroke is 4.375 on a 572.
Standard 502 is 4.47 bore and 4.00 stroke.

You may have aftermarket blocks Pete.
Are you sure they are a GM casting?

look for stamping on front of block on left side as looking from front on deck just in front of the head

i have a 572 that is 4.5 by 4.5.

Thanks for that explanation....That's how little I know about engines in general..now if I can get those casting #'s I'll know for sure if I have 540's or 572's

Rob I have serial #'s for both blocks (N6372 & N6373) but I don't think that identify's the the origin.
http://flagshipengine.com/ only built Hi Po engines from GM blocks...my issue is, are they 540's
or 572's?...........the son of the owner swears they're 540's yet the dyno sheet says 575's which totally
confuses me.......even if I find the casting #'s off the blocks ...would that even identfy what cu. in. engines
I now have in the boat?