bolt pattern

have a 69 impala i just bought and i want to know what bolt pattern they are
and what cars could i pull wheels off of to fit, preffered 14's or 15's. the
reason i ask is because the car came with 13 inch 70 spokes wheels w the
octogonal knock offs and im not a 13 inch wheel kinda guy AND i cant get the
knock offs off.
so im figuring ill pull some wheels at the salvage yard and take them w the
car to get the old ones off and get the ones i will be pulling put on in
their place.
which leads me back to my question, which chevys can i pull wheels from
that would fit? oh it has four wheel drum brakes if that helps any.
all help appreciated and thanks in advanced.