the previous owner did a transplant on my car!
 

My tranny mechanic just informed me today that the transmission on my SVX is actually from a Legacy? Seems quite odd... So they gutted the entire thing, and he said he did a lot of tweaking to get the most performance out of it. But does that sound right? Who the hell would do that? He said it had a junkyard tag on it, and whoever installed it did a pretty bad job.

The Legacy transmission bolts right up to the SVX. The problem (as Randy found out) is that the SVX rear end doesn't match the Legacy tranny. Ask your mechanic whether or not the rear end on your car matches the transplanted Legacy tranny.

Without a matching rear diff, the tranny's transfer clutches will bind and eat themselves in a matter of miles.