we have a 1982 coleman pop up can air be installed on this camper I heard that there was not enough support there Trisha

Look inside your camper at the ceiling and if it has some roof supports then you can install it in the roof. If the supports are missing then you will need to install supports before putting a roof top a/c unit on it. They only weigh 65 pounds but get much heavier going down the street with the camper bouncing.
I know all of the Starcraft comes from the factory now with the supports installed on them not sure what the older colemen's have.
Hope this helps