64 Valiant Dash Speaker

The AM radio in my little 64 works but plays sporadically because the speaker is shot. Does anyone know the impedance and size of the factory speaker so I don't have to get my fatass under the dash but once? I THINK it's a 4x10 and 8 ohms but I would like to be sure, so I can go ahead and get a replacement now. Thank you drive through.