I have a 69 Z with a 350 in it, here is my question. I have some of oil coming out of the breather on the passenger side valve cover, I have a pcv valve hooked up to the carb, (Holly 650 double pumper),and it seems to be working,but I always have an oil mess to clean up on my valve cover, Header,and down the side of my engine. Could this be just a bad seal on the twist-on breather??, I have tried a new one, but still have the same problem. Help!!!!!

Replace the PCV valve. I had the same problem, in my 350 untill I replaced the PCV valve. If that doesnt help you might wanna run an old school drain tube like the early SBC's. This is just a tube that runs in back of the block and drips back there. I doesnt work well with the new type breather system though. Maybe run a tube up to the air cleaner like the 70's cars. Or rebuild the engine.