Cyanogen Mod also known as CM 11 is now available for the Samsung Galaxy Core phone. This will allow you to enjoy vanilla android experience that is backed by frequent updates directly from the developers.
The development of this ROM is still in early stages though and quite lot of important things like Wi-Fi, Bluetooth, SIM card, camera and audio do not work. Since SIM card is not working you will not be able to make phone calls. However, memory card, and GPS module are working just fine. You can download the ROM from here.
Please note that there are a lot of bugs and we really do not recommend using this Cyanogen Mod ROM on your Galaxy Core if it is your daily driver.