I'm trying to find valve seats for a 5.3L cylinder head. Any idea's where to get them?

 

are they to bad for them to be re-cut? a local machine shop should be able to get ahold of some or be able to steer you in the right direction.

 

A friend is working on his heads and the valve seats were falling out. The machine shop he brought them to has no idea what to do with Gen III stuff. Their source doesn't carry valve seats for them from what he said.