some info on a 440

OK sorry for the confusion it a 67 dodge pickup with a 426 that was bored out to a 440 is what I was told I already bought the truck and brought it home. Tried to drive it last night but my battery died. When I had another battery a few days ago it turned over and ran good I didn't getto drive it cause I think the trans is low on fluid. I was told by the owner that he bought it with a 318 and he devoted he wanted something bigger so he found a 440 motor out of a 68 charger but later after a friend of his saw it and said it was a 426 bored to a 440. He never new why it would the motor would overheat and the buddy of his said cause of the thin walls from being bored.