Slayte;
Just replacing the valves alone sounds "thrifty" and inviting, but as Tony and Lil'Johnny said, (paraphrased), the valve train is only as good as it's weakest component.
If you're upgrading, go all the way- hardened valves, hardened seats, and bronze guides. Yeah, it'll get pricey at first, but in the long run, you'll be rewarded.
Take a little comfort in the fact that this just involves the cylinder head on a Chevy; guys like me who insist on playing with old MoPars with flathead engines have to yank the whole engine to get this same job done!
Good luck!
