Exactly.The pullies are part of a hub that bolts on. Usually just one pulley for the belt drive on the alt and water pump. 2 pullies for ps equipped vehicles.
No harmonic balancer used.
Early 283 was the same.
Should be a notch in the pulley closest to the timing cover.
Measure pulley diameter with a string then divide that by 36 to find and mark 10 degree increments.