My first thought as I read your initial post was to wonder if you staggered the rings properly, like 36 sedan asked. I second the suggestions that you should first do a compression check on all the cylinders (36 sedan), and then a cylinder leakdown test (jerry clayton). Blowing a timing cover gasket sounds like a lot of pressure! I'd be tempted to rig up a pressure gauge with a rubber stopper and plug it into the oil filler tube as you have someone blip the throttle just for grins.

I hope that you'll come back with some hard data on what you find.