I do not have a interference issue with the windage tray and I do not use studs on the mail. Like I have mentioned before I have tried many times now to seal this up with different gaskets with Würth Super RTV Silicone between all layers (pan gskets and tray) Been trying without any silicone, with only small amounts in suspected areas. I've been checking for a flat pan rail and windage tray and everything have been washed down with brake cleaner before assmbly and offcourse checking for holes / cracks in the pan.

Could the angle of the engine cause the leak in the rear? Running a TKO 600 transmission and that makes the engine being tilted more that normal towards the firewall.