Aux Vacuum pump to assist brakes on '65 C10

['65 chevy lover]

The motor in my truck doesn't make enough vacuum because of the cam in it, and the brakes don't work near as well as I'd like them too. I've looked around a little bit, but can't seem to find much anything that would show me what I need to make a good auxiliary vacuum pump system. If anyone here knows about this I'd appreciate the help.

Thanks,
Bill