Make sure you have a baffle under wherever you put the PCV valve. I noticed that a pic you posted of the inside over the valve cover has the cast in, threaded bosses for the baffle, but it's not in place. Look at the inside of your old stock valve covers and it will be obvious why. Just imagine sucking up engine oil and dumping it in your carb...
If you use the twist on breather as your oil fill, you might switch sides for your valve covers so the fill is in front instead of in the back.
If you leave the PCV out you will definitely find oil leaks that you never knew you had!
