I think I solved the valve cover gasket issue this weekend. I tried the FelPro gaskets and they leaked. This time it was the other side. I *almost* drilled a hole in the 4 cam replica covers but decided to just jump to inevitable. I tapped and vented some original stock valve covers. took about 20 minutes to clean 'em up and get the vents installed. I installed them with some standard cork gaskets. No issues as of yet.
While running down the valve cover issues I found that the oil pump may be seeping somewhere. Boo. I bet it's the silly 'ribbed' aluminum cover that's on there. It's a good melling pump, can I use the original oil pump face plate? Or are there better options? I also found a weeping stud in the sump. I kind of knew the hole was dodgy. It appears to be stripped. I need to replace a stud with a 'step stud' in the sump. I picked up the stud this weekend. Maybe I'll jump in head long and fix all these issues while I'm installing the cooler / bypass valve.
I'm just not a fan of working with oil lines. They tend to be prone to leaks and major messes. 
Ted