Lithrael

I have a 1981 2+2 manual 280z, whose starter I wrecked directly to hell.. Chewed up the gear real good. I'm having the worst time replacing it. I've bought two now from people that swore it would fit my car but niether works (one from a '75 280z and one from an '82 turbo automatic)... Does anyone know how I can find the correct part number or what model years will fit my car? And does anyone need two starter motors... Thanks!