Tap them with a rubber mallet. May take many taps. Go around them tapping, not on the flange area, but the vertical/sides of them. Sooner or later you will hear the gasket give.
Don't pry on them with anything. Unless you don't care about them.
Russ
Thanks for all the help, I tried a little bit of everything. I tried tapping with the rubber hammer, but that wasn't working probably cause I was impatient and didn't drum long enough, so I moved on to the 2x4 and some gentle persuasion, ie hammer, that didn't work either because I didn't have good angles or a place to really wedge that 2x4, so I opted for the good ol' fashion flat screwdriver and that did the tick. I pretty much accepted the fact that I would need new gaskets.
How much should I torque the valve cover bolts to? The Haynes manual does not say, it mentions something called "Rocker Cover" I wonder if that's what they call the Valve Cover?
I still can't get over how clean that lifter valley is...looks pretty low-mileage...
I'm sure there is a specific torque for valve covers (also called rocker covers), but I've never used it. Tightening the bolts on a valve cover is a bit of an art...you have to get them tight enough to hold without distorting the thin metal of the cover or the cork seal underneath.
Even if you get them perfect, you are likely to eventually get some oil leakage past the cork if you have a lot of oil laying up against the seal all of the time. A lot of rebuilders will smooth and enlarge the oil drainback hole in the heads to reduce the amount of oil staying in the rocker area. Best done with the heads off during a head rebuild...
Since those 5/16 bolts were the same as the bigger ones on the oil pan I torqued them down to 12 foot pounds like the oil pan specs (and that felt snug) but I would appreciate it if someone could confirm that for me by checking one of your manuals.