They have chains and balance shafts. A very common problem is the balance shaft seizing and wrecking the motor. They make elimination kits for that.
I know you're on the starquestclub national forum and I learned that basic stuff just reading around for a few days. They also have a great checklist of things to look at for new SQ owners...you should run through it. Low mileage cars are as much a curse as a blessing due to the lack of maintenance.
There's a vendor called 'Dad' that rebuilds the motors and knows everything worth knowing on that front.
http://www.enginemachineservice.com/