[XT6Wagon]

Skip that 4.6, as its HUUUUGE. Its the size of a old Ford 460 big block.

I'm quite certain that a GM LS family engine will fit, only concern is hood hieght and the engine subframe. Not the hardest thing in the world to make a tubular subframe, but either time consuming or expensive depending on your skills. Might not be needed, or just a modified stock one is all it will take. Just want it out there that its one of the few places you will see issues. People swap them into 240sx all the time, and people have swapped them into 300zx too.

GM and painless wiring both sell "hot rod" wiring harnesses for the engine that will allow you to run the enging without making a custom wiring harness yourself.

A stranger idea, but the Jag 4.0L V8's are suprisingly cheap. You want a 2000+ one if you go this route. It it definitely will be more work as no one sells off the shelf harnesses, but its a sweet little motor. The 4.0 with supercharger is a truely epic motor in its own way, but might have more issues getting it in. Mind its likely better and cheaper to just buy a 2000-2003 XJR right now and its much the same size as a SVX. Lincon LS/Ford Thunderbird uses a "3.9L" version but I have no idea what if any changes they made for those models.