Vacuum hose ports: plug with a rubber cap. Or cut the hose and insert a stick of appropriate diameter. Or a bolt. Or a golf tee.

Exhaust port (small tube): Unscrew tube and plug with a threaded fitting. Some guys cut, pinch and weld the tube.

The EGR Valve itself leaves a hole if removed. A small aluminum plate is easy to fabricate. If you remove the entire EGA adapter, it leaves a big hole, and as it is underside, not reason to remove it.

Thanks David
Most appreciated.

I'll set up a build thread once I see if I can get the ecu sorted

EGR - I would leave the adapter (EGR Passage casting) on the bottom of the manifold.

See GX-E section "EGR"

I'll take some photos once the manifold arrives and then start blanking things off

Thanks for all your help with this

Is the tps on the stock manifold a full function tps? If I had to go aftermarket ecu I think it would be needed.. Some of the earlier ones were more on off switches

I don't know. You can check the function in the 280Z Service Manual.

If you go MegaSquirt ECU, it can use either type, or no TPS at all.

What about loom?? What would you expect to pay to get it all wired up??

If you get the Datsun parts, get the loom too. Only 7 wires need to be connected externally, the loom takes care of the rest.

This is definitely a DIY project.

You can use no tps BUT you wont be able to use flud clear mode witch can be a pain in the arse.

flud clear mode?