Will a EF-AU engine drop straight in ready to go with ECU or is there more to it like looms & other stuff?

I know the conversion from i6 to v8 requires a lot of changes to looms & other issues but with the v8 is it a straight swap & go?

I thought it was 6 cyl??
Pete would be the # 1 on this....

You need to put the E-Series distributor in the AU block, just remove the crank angle sensor for the hole.

The ACT (Ambient Charge Temp) sensor needs to be re-located, it's in #5 runner of the HO manifold, but AU's have it in the intake pipe before the TB. I think you're better off tapping a hole in the AU Explorer manifold to fit the sensor in there, because the E-Series ECU will be looking for a hotter temp from the sensor than the AU ECU.

Use all of your ancilleries, injectors and MAF, everything else will bolt in.

Is this a 6cyl to 8cyl conversion?
EB-EL 5.0L is an easier proposition than an AU 5.0L conversion.
Aaron_EF8 has hit the nail.
Some other AU5.0 to E-series points are to with the 40p heads which can create header/spark plug clearance problems.
If you use EB-EL front accessories you need to switch to the EB-EL water pump which has a smaller drive hub than the AU one. Plus you'll need the EB-EL type harmonic balancer because the AU one will not work with the EB-EL stuff. Injectors are EV6 type on the AU so if you want to run these you'll need either adaptor plugs or you need to chop the original EB-EL plugs off the harness and add EV6 type. These AU injectors are 24lb/hr so you'll either need to run a Sprint/GT EEC and matching 70mm MAF or run an aftermarket MAF to suit 24's with a stock EEC or use a TwEECer and just change the injector size.
The TPS on the AU t-body has a different plug so you need to once again make an adaptor to allow the AU TPS to be used or adapt an earlier TPS which is difficult because the AU uses a wider bolt pattern on the TPS. Or you can switch to an earlier type throttle body with a TPS that plugs straight in.
The other option is to use the entire AU engine and harness which has it's own share of issues but is certainly do-able.

Pete.