I'm running a 427 side oiler bored and stroked. I use an original style (Ford 1965) rear goseneck breather,but I also have the bottom portion hanging in the intake manifold. This is original Ford stuff again. Looks like a metal basket with open sides, with stainless steel wool stuffing it full. I understand the basket of steel wool captures the
oil and allows it to drip back down without escaping the top of the breather. Also have a PVC valve in one valve cover (right side). I've never had an
oil issue, either street driving or racing. Just do it the old fashion way - it works.