Alden, If it was my truck I would unhook the vacuum line that connects to your vacuum advance on the distributor and temporarily plug it. Then take the truck for a ride and see how it acts. I believe that the distributor should have ported vacuum to it and that the transmission should have straight vacuum.
The brake booster line should have a check valve in it also.
What site did you post the pictures at? I'd like to take a look at them.
Good Luck,
Don
