1970 NOVA L89 ?

[Igosplut]

So another one appears to match the black one. I know never to say never but open chamber heads on a closed motor? (I don't see a plug). Doesn't make sense. And I know there is a poster here that did the ordering for Scuncio, and he stated that he tried to order aluminum head novas (in 70) and GM said no-go. I don't know for sure, but there doesn't seem to be much history (in today's communication world) with these cars. Just figured somebody would know more....