Yeah, the AW30-40 (or -43) will bolt up to the back of a 5-pot whiteblock, But then you'll have to sort out the sump, the engine mounts, the engine management, etc. That's a lot of hours before you have to jump through State Growth's infinite number of hoops for a blue mod plate.
Depends if you want a project or an easy fix.
The easy fix? Berry's or Monash Prestige in Melbourne could sort out a good B6304 for you quickly and get it over the pond for a very fair price That might end up costing less than replacing four slugs, replacing the bent valves (and maybe rooted guides) in the head, and maybe the rods in your present unit.
On the offchance there's anything of potential use to you from the dead XC70, I looked up the part numbers for the B6304 slugs, and they're different from 5-potters. (Oddly enough, the V8's pistons are the same p/n as one version of the 5 cylinders, so that's why I checked).
