American Standard K73 model.

American Standard 8002 model.

This thing has a vent system in the tank and it looks like a computer in there. i've got a steady drip from a chain hanging down from a round piece of plastic that runs off the ballcock assembly. Anyone know where you can get parts for this thing or if it's even worth trying to fix? it's a late 80's model.

i found the parts on-line. the ballcock is $190 and the backflow preventer where the dripping is coming from is $100. i suspect that all i need is a plunger kit, and the plastic one is $20. may be time for a new toilet, but i don't trust the 1.6 gallon ones out now.