Being that your ride is a FWD I'd first be checking the rear chassis rails just behind the swing arms to see if there are two holes on each side for the rear diff's moustache bar mount points. If they're not there, you'll need to drill and place a captive nut in the correct location for the rear diff to mount in properly.
Is the EA82t in good condition? They're prone to over heating and cracking the heads between the valves - while not detrimental to the operation of the engine, they can become so bad that they start to loose compression.
Bang for buck you're far better off going with the EJ22 conversion hands down. Better/stronger engine from the get-go with about the same amount of peak power as the EA82t.
While a loom swap from the sedan to the wagon is possible you'll also have to swap the instrument cluster surround and the indicator combination switch as these change between the series 1 and seires 2. An '86 L is a series 1 and will have flat grey coloured buttons where the rear demister button is located, head light and wiper switches are on the dashboard as opposed to being built into the combination switch on the steering column of the series 2.
You will also find wiring differences in the rear end such as different plugs for the rear lights, missing wiring for the rear window wiper and washer spray units.
But it is doable and has been done before. If you do the engine only wiring you might as well do the EJ conversion as it's pretty much the same amount of effort in the cut down and fitment side of things.
Also in some states (like vic) the EA82t needs to be engineered for the wagon as it "wasn't a factory option" on the wagon body, even though it is technically THE SAME chassis. Bloody nanny state!
Any other questions fire away
Cheers
Bennie
