Need help with prop valve

[68jimmy]

This disc brake upgrade is getting to be more of a pain the a#$ than it's worth... Anyway to the real issue. I have swapped the master cylinder/booster/prop valve from a 72 c-10 parts truck to mine. During the bleeding it seemed that the master cylinder was not working to the rear brakes. Yesterday I purchased a new master cylinder, bench bled it prior to install. Installed itm attached all of the hard lines and started the bleed process.
Front brakes, no problem. Get to the rears and I'm just getting a trickle... So I recheck all the lines and connections still the same results. So I start with the troubleshooting guide at cpp.
http://www.classicperform.com/TechBo...tm#tshootbleed

While testing the prop valve with a test light I find that it lights up. So I remove the switch from the prop valve and discover that the internal valve is towards the rear. So I take a small screwdriver and puch it forward, re-install the switch and check with a test light. All seems good. In following the guide it recommends that I open the bleeder valves on the wheels that are working ok, in this case the fronts. I do so and gently push the brake pedal all the way to the floor a couple of times. When I recheck with the test light it is grounded again! I remove the switch again and the valve is towrds tha rear once more.

Do I need to get a new prop valve? Is there any other tips or tricks I should try? Help!!

Thanks in advance....