Steven,

What year truck?

One style was used on 1954 and later cars, and, maybe 1956 and later trucks (your photos 2,3 & 6,7,8).
http://chevy.oldcarmanualproject.com/shop/1955/55csm0609.html

The other style was used on pre-56 trucks (your photos 1, 4 & 5 maybe).
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0619.htm

The "plumbing" (routing) of vacuum lines are different. Either style will work.