Tonight I replaced all of the cab lights and gaskets for $29! The cheapest I could find at the normal Chevy parts houses was $80. I posted the purchasing info here:
http://67-72chevytrucks.com/vboard/s...57#post6388957 . The gaskets were closer to plastic than rubber after being on the truck for so long. Very brittle and cracked so I just cut them off. Several lenses were cracked and they were all cloudy. The metal under the lights was pretty pitted and rusty. To bad these didn't get changed 10 years ago... The sockets are kind of tough to get into the rubber gaskets. The metal clips that are clipped onto the main hole under the light are the grounding points. Three of my lights didn't work after changing gaskets and I had to wiggle the grounds around to get them back on.