Why do I see some high performance engines w/ breather caps on the oil spout??????

Originally posted by stanger8172:
I have milled heads so should I have a breather that rbatson suggested?

I'm not suggesting them, I was just stating what I 'thought' they were used for (thought being the key word here). I don't know where I got that idea or if its true. I got that idea from somewhere, just don't remember.. Some of these other guys would 'probably' know better than I.