I have a friend who has a set of BB aluminum heads cast number 14011077 (118cc)bare nos still in gm box untouched what are they worth. And about what it would be to build stock no porting, polishing. I would like to use them on a ZL- 1 block (#12370850) I just picked up saturday. My plan is to build simular to L 88 spec but with roller cam and rockers. Open to all suggestions.