La 360 Oil Pan Gasket....

I had the same issue with my 360 Duster, leaked out the back of the oil pan so i tried a one piece gasket... still leaked. Finally i ended up buying a new Milodon oil pan from Mancini. It was pretty expensive for an oil pan but solved my issue, also used a one piece gasket with rtv in the back and front corners. I was able to shimmy it up but had to remove passenger side header. I think i dabbed a little super glue in a couple spots to hold the gasket. Still no leaks.

Also do you have a pcv valve, maybe you are getting to much crank case pressure?