Will the EA82 and EA82TURBO work in any brat without major modifications?

It should, but I warn you about the ea82T. Not a very good motor. I have had my share and have gone through them. You are better off staying with the ea82. Way more reliable. If you want a turbo motor, go to an Ej. 

It depends.  What engine is in the Brat now.  What type of EA82 are you trying to transplant?

Carb to SPFI or turbo is a lot of electrical work on top of any mechanical.

It's a 80 with a EA71 (1600). I want to put another lower mileage engine in with the least amount of work. If an EA82 or EA82T isn't that easy than how about an EA81 (1800) or EA81T?

I would go the ea81. I love those little motors. It will be hard to find a ea81T.

I took an ea81 and replaced the ea82T in my Rx just because it is so reliable and great on gas. Not the fastest or torquest but great motor. 

I had the ea81 in my Brat and wanted more so I put in a 2.2T. Yes it is a lot of fabricating. I took the  whole legacy front suspension and cross member, disconnected at the strut towers, and dropped it as one unit and then lifted and fabricated mounts so the legacy bolts up like on the legacy. But it is all custom and a lot of work.

 

So really, ea82 is more power than the ea81 but those are the options. Like I said, my ea81 runs like a swiss watch.

EA81 to EA81 would probably not be too bad. Both carbed.

 

Most of the power increase in EA81 vs ea82 is due to SPFI, iirc. I've seen threads where the SPFI is swapped onto EA81.

 

But swapping from carb to spfi or turbo is big electrical on top of mechanical.

 

If you want reliable, you don't want turbo.

 

The overhead cam engines EA82 and up are wider than the old pushrod engines, and require more mods to the frame I think to get them in.

I believe the frame rails of the EA71 (1600) Brat are narrower and the EA82 will not fit without cutting and welding. I remember seeing that somewhere. I would never substitute an EA82 for any Subaru engine. It's not that they're a bad engine, but the cooling system was barely big enough to support the engine and they have to be maintained religiously. Do the EA81 swap and stay away from the turbo versions of either. Turbos are nearly non existent for replacement and are at the failure age. Finding one to swap in and work correctly can be costly. If cost isn't an issue, then no worries.