Tiny, imagine the housing with a hole about 3/4" drilled in the top of the housing. Then imagine a rubber grommet fit in the hole with the top of the bulb fitting up against it from the inside of the housing.
...I'm with Joe on this one but I guess back in the day it would have been "sufficient".
Unless the pickup housing is different from the car there is no such thing is the problem. I'm going to assume they are different and just shut up I guess.
