I'm afraid that I dunno what the partcode is but I'd suggest that you have a look at
www.300zx.co.uk forum. I'm sure that they'll be something on there.
Also I had heard that the AFM for the 300 was very pricey e.g. £300ish. My brother has a 300 and he was thinking of replacing his AFM (could be knackered) and I think that was how much he was looking at.