It looks like the PO got the diff drop from Darlington so it's a 2" drop.
wierd that they got the Darlington diff drop though but didn't get his crossmember drop brackets. Would've saved them some significant work on the install.
The crossmember modification was much easier on the Calmini bar than it would have been for the OEM. The crossmember drop brackets are just bolt on though so ... easy/peasy.