Increase Y axis max length?

I modified my bed to 220 x 275. I tried pulling up the EEPROM settings in Repetier Host but the axis length settings are not listed there. Is there a way to increase the max length of the Y axis?

You have to modify the sources of the firmware and recompile.

Hi, first off just want to say thanks for all the effort you put in to this firmware, it looks and works great!

Ok, so I got 4.0.0 source from Github, edited the bed length, and uploaded to the printer. but I get the mismatch screen for the LCD and mainboard. My question is, Do I have access to the source code for 4.0.3 so I can edit that and get my printer up and running? I only see links to the hex files. Or is there a way to change the version number of 4.0.0 to 4.0.3? Thanks again!