Timing Marks on Balancer

I have a 360 (74-79) that I did not build. It was in the car when I bought it and I'm having an issue with locating the correct timing marks on the balancer. When I rotate the engine to TDC (rotor pointing to #1 wire, piston at top) the marks are nowhere near the pointer. There are 2 or 3 marks on the balancer but the closest one is about 4" clockwise from the TDC pointer. Someone timed this motor when they built it but there is no mark where I think TDC is...so what could be going on here? BTW, the car runs fine, I just want to be sure it's set right...because tinkering.