Damper (at least you spelled it right) is pressed (or pounded) onto the crank. It is similar to the early Chebbie V8 cranks where everybody hammered the damper back on. There is a woodruff key holding the rotational position....

As I remember, the damper goes to a shoulder on the crank. You potentially can drill and tap the end of the crank so you can add a bolt retention device. The problem with doing this is the access to the end of the crank since usually the radiator, crossmember, or some other feature is in the way. If you have a right angle drill and a stubby bit (dont risk harbor freight crap here) you might swing it. Tap it something like 1/2-20 or bigger. Fine threads are better. Grade 8 bolt is a must. You might go buy a Chev V8 bolt and match that. Dont hammer the damper on, use the bolt to pull it on. It sounds like you already have a slip fit clearance but if something is out of round, you might have a problem.