Hey nice coupe!
What you need for the 4wd conversion is:
- rear “K” frame that the suspension mounts to. This will also require the swing arms with the stub axle that is splined and rostered. You’ll need the drum/disc and associated parts too.
- rear diff and drive shafts
- moustache bar and mount points left and right. This part holds the back of the diff in place. To fit this to the coupe you’ll need to drill holes and work out how to get annut behind the holes. You could get lucky and find a set of holes with a captive nut in place but it’s not always the case.
As for the AWD box, you’ll need to make a custom gearbox crossmember. There are details around here on how to do that. L-Rex on ausubaru.com.au has some awesome details of this in the build of his EJ turbo L series. You can source MPFI or turbo MPFI L series front shafts that will fit the EJ AWD box output stubs no worries.
Just make sure the gearbox comes with axle stubs and not the female setup where the driveshaft goes into the gearbox - otherwise it’s custom drive shaft (same if you do the 5 stud conversion with EJ brakes)
On the topic of brakes - standard EA will do if you’re not street racing and drive it appropriately. I’d be givin the whole system a good service though and throwing a set of braided brake lines in for good measure. Rear discs would be a beneficial upgrade - but make sure they’re the 4wd ones and that you get the hub, disc, backing plate, caliper and brake line that runs along the swing arm as it’s different to that of the drum brake.
No adaptor plate needed for the EJ engine to EJ AWD box - your clutch cable will slip in and do the job. If the clutch was operated by hydraulic from the donor vehicle then you’ll have to source a cablemoperated clutch fork and cable mount (or use yours from the EA box).
Engine wiring is always the biggest headache for most. Get that sorted and you’re off and away!
Also remember that the EJ AWD box is setup to run a larger diameter tyre to that of the EA’s. You could try doing a diff ratio swap to compensate but that’s pretty involved and you’d want to start with an Impreza or Foz box from my thought/research. Or run the Impreza/liberty sized tyre and do the EJ brake upgrade too.
Once you’re all done it’ll be a sweet ride!
All the best with it!
Cheers
Bennie
Edit/ps: I should’ve added that to get the 4wd rear end parts get an L series 4wd donor - sedan or wagon, turbo or NA (turbo will have rear discs and possibly a clutch pack lsd if both haven’t been sold off already). Then you’ll have all the bits you need.