I have done that before. Just hold the carburetor throttle wide open and move the governor arm the same direction as far as it will go. this should cause the flyweights on the governor to retract. Measure between the holes while you hold it. It may help if the governor spring from the throttle is disconnected when you do this.
The distance between the rod holes in each lever could be longer with the carburetor throttle closed because the governor shaft can swing away from contact with the sleeve on the governor assembly. That is why you measure at wide open throttle.
If your rod doesn't fit the holes snugly, use a damper spring between the levers to take out any lost motion so the governor will not surge. If you don't have a damper spring, I have re-purposed other small springs in a pinch.
If the engine still runs away, you may have to take the cover off and verify that the governor assembly inside is intact.