Going to look at a 5.3 today couple qustions

[MAK191]

Ok, I'm going to look at a 2002 5.3 The engine has about 120k miles. It is a complete engine top to bottom with computer and wiring but missing alternator and starter. couple questions

1. How do I verify this thing is a 5.3 and not a 4.8 is it stamped on the block or do I have to decode a casting number?
2. Any problem areas to look out for?
3. Any additional advice is appreciated?

thanks in advance
Mike