I don't have any closeups of the valve itself. The truck is now in pieces. I could take one in a couple days (the truck is 150 miles from me). However, my valve was replaced about 35 years ago. As I recall, the replacement valve had a slightly different appearance from the original even though it was a GM part installed by a Chevy dealer. For my restoration I bought a new one from Classic Industries. It is somewhat different from my current valve, but it looks like the pictures in most of the parts catalogs. I bought it 3 months ago for $29.99. They now list it at $60.99! I'll attach a link, but shop around. For example, LMC has an illustration of a valve that looks the same for $26.95. Their part number is 32-0653.
Link to Classic Industries part:
http://www.classicindustries.com/truck/parts/17153.html
Link to LMC's part:
http://www.lmctruck.com/icatalog/cb/full.aspx?Page=118
One other thing. If you look at the picture I posted, you can see the vacuum line pass along then under the 3/4" heater hose from the water pump. it attaches to the side of the top of the valve which is partially hidden by the 3/4" hose. The main difference between my valve and the new ones is that the vacuum line enters fron the side of the valve body vs. entering from the end.