360 now 408 stroker oil pan still leaks!!

Use black RTV on all oil gasket surfaces. I had the same problem but it turned out the header was blocking the valve cover from sealing in the back near the fire wall and when I launched a small stream of oil was running down the space between the head and the block but looked like the oil pan was leaking. I felt like an idiot after I found it but would have bet money the rear seal on the pan was leaking.