1970 dart for sale big block $8500 firm

In your last pic, look at the machined flat pad just back to the right of the thermstat housing. If you look right down on it, you will see the displacement of the engine. Probably a 440 on there somewhere. The letter in front of it will tell us what year it is. For instance, D 440 would be a 1968 casting. (I think D is 1968!?)