[DeTomaso] Bronze or Steel Valve Guides

[Tom Borcich]

I'm redoing my heads and need any suggestions on pros and cons of bronze vs. steel valve guides? 
I have closed chamber 4V heads. I've read that bronze guides may not be as durable and seize up 
(maybe because they didn't have the right clearance to start with)? My cam will not have lift of more than .580. 
The exhaust guides were already done (not my original heads) with steel and I'm not sure if they should be redone.

Tom