I have a 1970 455 olds. It has been resting on a tire in my shop for 8 years. From my understanding 70' was the last year for the high compression motor. I can get more #'s that I will post later.

 

Here are the issues. It's 41 years old and it's been sitting for at least 8 years. It's going to be a core engine to whomever buys it from you (if their smart) so don't expect big bucks just because it's a 70. If it turns over it's worth a bit more, but not much.
If you can fire it up to prove a non smoking/knocking engine that will help more than anything.
In it's present state I'd lay out $200. If it turns over by hand I'd give an extra $50. If it runs I'd say $350-$500 at the outside to the right person.

 

ok thank you very much I had someone offer $50 but for me to scrap it I could get more out of it. Thanks for your help