Hey Grigg.
It looks like your thread is a big hit. I never thought you'd get this much action. Then again, I can count on 3 fingers, how many of these engines I've seen in a forum.
I went through my file and I got the part # for the head sets.
Some counter person researched the application (351 V6) for me and came up with a Felpro HS7962SB1 . Priced just under $52.00 each. I guess $104.00 isn't bad for a complete top end gasket/seal set.