The Al-Khalid is an MBT jointly developed by Pakistan and China during the 1990s. The Al-Khalid is unusual in that it was designed to be adaptable for manufacture, so that it can be easily integrated with a variety of foreign engines and transmissions. It is based on the Chinese Type 90-II. The final tank design resulting from a decade of co-operative development was designated Type 90-IIM. The Chinese company Norinco showed the new Type 90-IIM during the March 2001 Abu Dhabi Defense Expo, under the export name MBT 2000. The version powered by the Ukrainian KMDB 6TD-2 1,200 hp diesel engine coupled to a French SESM ESM500 5-speed automatic transmission, intended for domestic production in Pakistan, was named Al-Khalid.
Engine and transmission aside, differences AK and VT1 may mainly whether or not all Chinese components are used. E.g. sights and fire control system. Prototypes were demonstrated with various fire-control systems of Chinese and western origin, but the production model Al-Khalid MBTs use a Western fire-control system (FCS) and gun control system (GCS). AK1 uses Sagem third-generation thermal imagers. In the MBT 2000, the Chinese Norinco fire-control system takes inputs from ten sensors.
E.g. The gun of AK is a modified variant of both the Chinese ZPT-98 and the Ukrainian KBA-3 series of 125 mm smooth bore gun, and I presume MBT-2000 could fit all (but ZPT-98 most likely standard). Initially Pakistan got gun barrels from France but now locally produces its own.
VT-1A is a new export variant of the Type 90II and has Chinese-made interior, turret, gun, electronics and armour. It also has a Chinese 1300 horsepower engine.
Peru leased five VT-1A from China for trials in 2009. The Peruvian government had expressed interest in purchasing 80–120 units to complement the fleet of Soviet T-55 tanks in service with the Peruvian Army. Peru decided to buy MBT-2000 tanks. The deal was blocked as China did not obtain permission to re-sell some Ukrainian components (including engine and Varta Active protection system).