58 365 Caddie block and Heads

I am about to cracktest the block and heads and was wondering if anyone can tell me if there are any inherent problem spots to look for on these?

Cheers.

 

the head are known to crack. I think its between the center 2 exhaust valves. Im not exactly sure because I had a good set of head but I read alot about cracked heads never heard to much about cracked blocks.

 

Thanks for that Noland,I will pay particular attention to that area.
Cheers for the reply.