So, aside from all the arguing here, I just finshed lifting not one, not 2, but 3 1990 legacys.. in the past 2 months. SO, I will chime in with what I know.
Also, I helped SJR make his prototype EJ lift kit, and thus, I also know about all the camber, offset, rear trailing arm offset, AND outback/forester/legacy strut height and top hat issues.
First of all, if you take a 1990 legacy (i own one myself) and plop in some 97-99 outback struts ONLY without spacers added- you will gain about 1.5 to 2" of height.. it wont eat all axles, keep in mind, that it depends on the condition of your axles already in your car, and what brand they are- I have noticed that different brands of axles (OEM vrs aftermarket) have slightly different lenght tolerances and will either work fine, or click till they break...
If you add spacers that don't correct for the offset drop (because the strut top mounts are not parallel to the ground) it will stretch the axles out further and also create massive camber issues... this is why the properly made lift kits have funny angles in the strut dropping blocks.
the reason you should only do a strut swap witout spacers is because of the camber/axle length issue- if you want to add any more space beyond what the outback/forester struts give you, you should consider using a full lift kit that will space the crossmembers and other suspension mounts downward too- it helps keep your car drivable for a longer time without breaking. it also is not really too hard to install.
here are the 3 wagons I lifted in this past month-
the white one was also an automatic- I converted it over to an ea82 5spd dual range with the adaptor kit- the parts price adds up, but its actually not to hard to get it all working... a 5mt legacy trans would be bolt in...
this wagon is the one I lifted with the "prototype" SJR lift kit- and fixed a problem with the rear lift blocks that mount to the front part of the leading link on the suspension- we drilled a second set of holes, so that the arm could be moved back, since the legacy pivot blocks are shorter than an outback's blocks- without the holes or the outback pivot blocks, the larger tires would rub on the forward part of the fender/body.. this corrected the issue and centered the tire in the wheel well.
So, that makes 4 lifted legacys for me, (also, 3 lifted EA81 wagons, and one strut-lift impreza wagon) I think I might know what I am taking about and have some experience with this.
hope I this helped, and lemmy know if you have any more questions about getting the legacy lifted without destroying axles.