The JZA70 only ever comes with a 2.5 twin turbo, not a 3.0 turbo as you say you have. If you have indeed got a JZA70 with a 3.0 in it then its a transplant, probably because of a blown original 2.5 engine, although this seems unlikely. Are you sure its a JZA and not an MA 3.0 GT? (these normally have similar to jap spec compared to our UK versions). Check you VIN and log book *and have a look at the engine !!!!) and let us know what you've actually got.
As for the digidash transplant, its a lot of work...stick with the dials.
adi
PS if you're in the UK i presume you've joined UK supras ? (and dont forget the new mkiii bbs below)