Ramesh

Hi all.. I have a 1989 Hyundai Stellar . 1.4 , 4 speed manual Transmission, car is in very good overall condition as per the other stellar s in the country , i would like to fit an automatic transmission to my car , in that case , can only a auto gearbox be fitted ? Or should the engine & gearbox both has to replaced ? If so how can i find a donor unit ? My name is Ramesh, and i am from SriLanka. Thank you .!