Cargo pack installation

[Skymaster337B]

Has anyone ever installed a cargo pack on an airplane that didn't have one from the factory?

My question is: do all Skymasters have the rivenuts already installed to add on a cargo pack, if there wasn't one originally installed by Cessna. Or if I buy a cargo pack, will I need to drill holes in my airframe and install the hardware?

If I do have to install the hardware, how do I know where to install the hardware and pack? Since the maintenance manuals do not mention any alignment marks.

Thanks,

Rob

Snrpilot@aol.com