Jason, there are several variations of that particular head casting. If you research "LS3" cylinder head, you'll see what I'm talking about. I doubt you'll find another 821 casting, not needing work, but I could be wrong. Hopefully you can. It's difficult to find CORRECT info regarding your particular casting numbers chamber size, port volume, etc. There is a lot of conflicting info out there.
If I were you, I'd buy replacements as a pair to ensure equal chamber size, port volume size, etc. I understand the money side of this, but I know you hate doing things twice as much as the rest of us do. Here's a decent price on the equivalent head that you have. You can actually buy the LSA heads a little cheaper from Summit, but you'd need to compare volumes to ensure your getting what you actually want, and not losing power due to compression ratios, etc.
http://m.summitracing.com/parts/nal-12629063