That's the inflator bottle for the space-saver spare tire
werent those blue as well?
In 1976 they were blue in color. I have an original one.
most 77's I've seen had this red bottle, but when I got the car it had the blue bottle in the trunk with the tire.
my 77 has the RPO code N65 and really doesnt mean the tire got the red or blue bottle. I think it was the size of the tire.
being a 14" or 15" rim. and could of been one of the things changed when the shaker went to the taller one.
maybe John Witzke has a different RPO code as I know his is the red bottle.