I like the Fel-Pro "lifetime" blue gasket sets, but Edelbrock says that the Permatorque Blue's are for stock type cast iron manifolds only, and that they are not to be used for their aluminum manifolds. They also say to use only Locktite 598 OEM HT Silicone as others may damage O2 sensors - never heard of that before, and hard for me to see how silicone on the oil/water side affects O2 sensors? I'll probably spring for a tube, just to be safe, and it's not an issue for you on a '69.
If I had a leak that I could watch flow I would look first to the valve cover, and being sure that I did not have a gasket slipped, loose bolts on cast or too much torque on tin covers? Maybe Dave will come in with some Ford FE mantra for intakes & oil leaks