I am replacing my stock valve covers on my L03 with GM Performance Parts chrome bowtie covers. I removed the bolts and took a rubber mallet and a block of wood and hit it in a few sections, but the dang thing wouldn't budge! Any trick to getting these off?

 

Keep working with it.

 

LOTS of patience. That is if you want to keep them in useable condition. Did you hit under the lip with the wood, or just bang on it in the corners?
A lot of people loosen the bolts/nuts and then warm up the motor, then try to take 'em off. Never tried it as I seem to be lucky with that sort of thing. Same with heads and the dipstick tube. It's one of those things I guess. Just so you know, I have seen some people really mangle their vc's too, so you can wreck them if you get pissed while you are working. hth

 

I always had my best luck with a screwdriver. I would work my way around the edges prying on it. Course, its easier when they are already leaking!