I don't believe they are the same frame, but its been a long time since I've had one of each around to look at.
The frame on the 70s Dodge trucks drops down under the cab and those rear cab mounts are added to the side of the frame, and the front two bed mounting holes are brackets also added to the sides because of fuel tank clearance.
The club cab is 18" longer then the standard cab, the the rear cab mounting mounting brackets are located in a different place, and that means the front bed mounts are in a different location as well. I also suspect the drop under the cab is slightly longer under the club cab, but Dodge did have to accommodate for the fuel tank, so the drop might not have changed much.