Catalytic converter, how long do they last?

I've got 120,000 on my 95 Delta 88 and never changed the catalytic converter, it passes the state test for emissions no problem. How long do the converters normally last?

Almost always last for a very long time. As long as your engine is not running lean or rich all the time then the catalytic converter will last pretty much the life of the vehicle. Once your vehicle is running lean or rich then fix that problem before it poisons or clogged and eventually fail your catalytic converter.