So what I have found out so far. F72 = Heavy duty rear springs GV4 = 3.36 diff ratio L36 = blue high comp 253 M11 = floor shift M20 = 4 speed, 6.55:1 1st gear N67 = Rallye wheels, Var 2 (commodore slew rims QCP = 255/70R16 tyres ( another oddball ! )??? T57 = U17 instrument cluster ( oil.temp,volts,clock & fuel ) V01 = Heavy duty radiator V8J = Tinted dash panel lens XS5 = 510 upgrade ( whatever that means ) XW5 = outback pack XW6 = Metallic paint ( which in your case is Tahitian Blue with light blue vinyl interior ) Currently in the middle of doing a body off rebuild of it since I did not pass blue slip. I have build papers I have original service manual Extended warranty paperwork And it all matching numbers and vergin block that has never been cracked open.