60k maintainence

Vehicle Information: Model: Carrera 911; Year: 1984; Body Type: Targa; Engine (type, size, modifications): 93021-64E; Total Mileage: 60248;

I hear there is a 60k maintainence check that should be done. Can you tell me what it consists of? How much does it cost and is it critical to the maintainence of the car? My car has 60248 miles and was bought used. I do not have the maintainence record from the previous owner.Thanks