questions about valve seals

[iamseth]

I think mine need to be changed. I installed new spark plugs a few months ago to help settle a rough idle, and it worked! However, slowly the rough idle came back and when I inspected the spark plus last weekend all but 3 (4,6 & 8) had a some build up and were pretty black on the inside.

So, my question is this; Would changing the valve seals fix this? And if so, should I attempt it myself? This would be something I've never done before.

oh yeah- it's a 1972 C-10 400 bigblk.

thanks!