It could be the intake gasket or intake manifold. I had a Performer RPM that kept having
oil leaks into #2 and would could the plug Tried to change gaskets twice, the second time we noticed that the intake manifold was a bad casting and would wobble side to side (lie a table in a diner) and when that gasket failed, ordered a new Performer RPM intake and it was square. Replaced it and 5,000 miles later everything was still running fine. No more fouled plugs or
oil leaks.