I need some brake help

[muckyp]

Let me first say that this truck has been sitting for several years now. The master cylinder, brake lines, calipers and all brake components were new (well actually they were installed new by the PO, but had been sitting for several years). So the problem is I can't get the brakes bled. I bench bled the master cylinder and reinstalled it on the truck and attempted to begin bleeding at the right rear wheel with one of the mighty vac brake bleeders. I got nothing!
So I then began reading on here about brake problems. I read one about the lines being clogged so I disconnected the brake lines and blew air threw them to confirm that they were clear and they were.
Can anyone suggest where my problem might be? Does it sound like the proportioning valve is bad?