I didn't end up buying this for myself, but I thought I'd pass the info along:

"Y70" flywheel, Nissan part # 12310-Y7056 (supercedes old part # 12310-Y7000). I think it was out of an '83 Maxima. They're asking $75 for it, and it needs to be re-surfaced. I chose not to buy it because my local machine shop wants too much $$ (for my taste) to resurface it. Its at General Auto Salvage Co. (in New Hampshire) 800-562-3845. Ask for Bruce. He verified that its got "Y70" cast into the back side.

I have two of those as spares plus the ones in my 810 and Z. They're really not worth $75 for a used one. I picked up the ones I have have for $25 ea at the junkyard IIRC. In fact the one I put in my Z was less than that because it was during one of their 1/2 price days. Plenty of Maximas in the junkyards out here. People take the crankshafts from the diesels but for some reason they forget about the lighter (somewhat) flywheel. -Y7000 is the OEM number for the 810 and -Y7056 is the OEM number for the 910 (Maxima) but it's the same flywheel.

Thanks for the info Stephen, I thought they were more rare than that because I had a hard time finding one

I wonder how much difference there is between that flywheel and the ones used in the 6 bolt crank four cylinder cars like the L20B or the Naps-z.

I would have no clue about that

That's a nice looking 810 you have there, by the way