AFAIK the Nissan part only fits these engines, so I don't think you'll cross it to a US Nissan alternative.
In the past I have overlaid the Garrett GT Oil Inlet Gasket over the Nissan RB25DET Cylinder head oil drain gasket, as we keep both gaskets in stock.
Both the central hole and the bolt holes line up fine- so all the critical parts will function perfectly. The GT gasket has M8 bolt holes, while the Nissan has M6, and the GT gasket is
slightly bigger and hence
slightly overhangs the outer edge of the flange.
None of these will be an issue and you'll end up with a professionally produced gasket for $2 that I'd be happy to fit on my own engines...
Hope this helps
