The differences are in the TCM installed within the valve body.
I recommend getting any salvage yard VR30TT transmission, and swapping over a known good TCM of the same part number from your Z. I did my entire swap for $1300 myself. Even if you had to pay a shop, you're coming in WAY lower than putting in another anemic OE Z trans. at the dealer.
For reference.
Forced Induction & 7AT 370z Info
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