I'm a little confused about a section of the L28 motor, I currently own a '77 & '78 280z (just bought in very nice condition). I know there are slight differences between the two years, but have found multiple FSM's for both years showing 2 different variations. Can anyone tell me which one is the correct setup for both years?

Thanks

Diagram1.pdf

Diagram2.pdf

My 78 had the 'Diagram2' setup.

As far as I'm aware, there's only one official Datsun publication per year. The '77 and '78 are very similar, and I don't think the differences have much functional consequence, but there are certainly a few things they changed. Anyway, the Diagram 2 looks like my '78 with regard to the air regulator plumbing.