340 Static Compression Numbers and Test Procedure

You could pull off the timing cover and see the front edge of the front journal of the crank and see if it is cast or forged. Of course it does not answer the balance situation 100%.

It is a bit tricky to get loose from the pan (you may have to loosen the pan) but it can be done. Putting the cover back in place is a certain procedure.

The timing chain can be pulled off and that key replaced. That is not good....

Did you need a puller to remove the damper or did it just slide off the crank snout?

BTW, clean out the crud from the threads inside the snout. When the damper bolt get torqued down to that high torque (135 ft lbs), those threads see some real strain.