timing issues with a 280z turbo

when i set #1 @ TDC....the timing mark is aprox. 90 degrees before the 0 degree mark on the crank......i assume the harmonic balancer is defective???

am i correct???or is there adjusment like the cam timing and its in the wrong position?

what degree of advance should i use for the ignition timing?

the engine block casting # is F54 followed by a 0701A, s/n is L28 513794

the head casting number is P90

the computer is A11 or All-604 420/ L28 / 8Z13

the engine does have a turbo also

Is there a way for me to find 0 degrees on the crank without pullin the front cover....ie, is there a key way that is at 0 degrees

Thanks,

Ed G