[Too Many Projects]

I have a pair of 3931063 heads, both dated K29-8 and the matching 3931067 intake, date K30-8. Block assembly date is 12-04, so they were right off the build line. The engine appears to have a lot of miles on it, so the heads will likely need a rebuild.
Seems these aren't highly sought after parts and only desirable for an original rebuild. With that, how much can I expect to get for them?
I bought a set of 840 heads from Kurt for the build, so don't need these.
I'm also curious as to what I can expect to pay for an original L78 intake for the heads. No particular date needed. The engine will be installed in my '66 Chevelle and I'm guessing a 1966 date code will be difficult to find and more expensive than it will be worth to me.
Thanks, SYC gurus !