I`ve got a 64 Chevy with drum brakes, and I`m looking to go to power assisted drum.
A single master cylinder without a booster is really sad.
The bolt-on kit new is a little much, so I`m looking elsewhere.

Would the setup from an `80 Malibu work?

If so, will this be an easy swap, or not?

The set up from an 80 Malibu will not be easy. You will be better off using a booster from a 64-67 Chevelle and any disk brake dual master from 67-72. You will need the proportioning block for disk brakes and do a little replumbing from the master to the block. The 69 t0 72 disk spindels are also the easiest to put on your car although others will fit. If you just want power drums, a single system will work as well as the dual and all you will need is to add the booster. If you email me I wil give you my opinion on putting the '80 spindels on your car.