I have a SBC 383 in a '66 Nova SS that should make right around 425-450 HP so I'll no doubt put my foot into it now and again. So given that info, what are the pros and cons of the different types of valve cover breathers? I've heard that some that "push in" tend to pop out and leak oil under hard acceleration etc etc. I have the cast aluminum Bowtie valve covers that have no holes in them right now. So I don't want to screw them up with the wrong application. Your help and comments are appreciated.