If you go over some old posts, you'll see how simple to inject the log is. There is a way of making it work, but you have to make a line of best fit for the injectors. The front runner dips at 25 degrees, the rear at about 40. So if you settle on a 30 degree dip, and follow the Hillborn and Offenhauser aproach, you can stick with the existing exhast ports, do some cutting, and end up with an EFI system which uses most of the existing log as possible, but has a single throttle body of a 5.0 or 4.9.
There is nothing hard about it. Use an extruded alloy fuel runner, and settle on a Megqsquirt, SDS, or Delco EFI control unit.
Once you sit there looking, a big bolt of lightnening will hit, the :idea: will strike, and you'll see that the log is an assett, not a disadvantage.
The Datsun/Nissan L26/L28 efi intake won't fit the log head easily, as the bore spacing is 3.8125", not 4.08". So there is about 650 thou offset at number one and six runner, while the centre runners are out due the the phasing of the wider spacing of the centre runers on the little Ford I6.
With some work, the manifold and injection runners could work as the Nissan 280ZX casting is quite thick.
Just my 50 cents. I've almost done my EFI log mock-up.