What are you looking to do with this rebuild? Mild? Wild?
Can you give me some info on your heads and block?
Look on your heads, above the exhaust ports. There will-be some letters cast in the head. Dove, D3, Dooe-r. On the block on the side will also be some castings. I like to see them also.
Once we get that info we can go from there.
Here is what you are looking for.
Heads
http://i55.photobucket.com/albums/g1...ski/dooe-r.jpg
Block
http://i55.photobucket.com/albums/g1...i/blockID1.jpg