The wot_90.3998_8B.3905_client.patch file you have requested: Official Patches / v90 / World of Tanks v9.0 Patch (US) - 2.63gb is not available. Perhaps try browsing all files for the game World of Tanks and upload any files you want to share or are missing. This is the only information we could locate:
This patch updates World of Tanks to version 9.0 New Content Includes:
New game mode: Historical Battle: Face off as specific nations and vehicles in battles based on real conflicts. The following historical battles are available: Battle of Kursk, Battle of the Bulge, and Operation Spring Awakening
"HD" tank models: Available for a select number of vehicles for the time being.
New German vehicles: Pz.Kpfw. IV Ausf. A (tier III medium tank); Pz.Kpfw. IV Ausf. D (tier IV medium tank); StuG III Ausf. B (tier IV tank destroyer)
New Russian tank destroyer: The SU-85I is being added to the roster of Soviet vehicles. This Premium vehicle joins the battle at tier V. Initially, this vehicle will only be available directly from the Premium Shop.