I ended up using every trick in book sealing this. I used a steel reinforced one piece gasket. The two spots in front I RTVd with black. Built it up before install. As well as rear sealing surface. Let set up over night. RTV gasket to block. Bolted it on. Let set up overnight. Removed bolts and used RTV to Allah pan to block. Making sure to get corners with RTV. Now normally I will not use RTV for this gasket. But I was at a loss what else to do.... We will see...