In short, Yes, you can put a new mark on the balancer to align with the TDC mark on your timing tab. Obviously you need to have the engine at exact TDC and then mark the balancer with a pencil, remove it and cut an accurate groove across the damper with a hacksaw. I would also suggest marking that line TDC or 0 with a set of number and letter stamps and running a contrasting color paint into the new groove so it is easily seen. Leave the old mark the same color as the rest of the damper.
Before you go through all that give the damper a very close inspection. If the elastimer ring is cracked or otherwise not like new then in the long run you'd be better off getting a new damper with the correct timing mark on it. Groove worn in the hub from the front seal can be repaired with a slip on repair piece. It is the repair kit as the SBC uses. I've used them a lot and have no problems with them on street and mild performance engines of all types.
Mike
