Just simply changing the name of a game through param.sfo editor, doesn't work. You'll need to do several things....
for the game you mentioned (gtav):
First, need to find a BLES01807 eboot to replace the BLUS31156 eboot, you already have.
Second, you need to change the game id in the param.sfo from BLUS31156 to BLES01807, save it and replace it in the game's folder.
Third, inside the gtav game folder go to: BLES01807\PS3_GAME\LICDIR inside the LICDIR folder there should be LIC.DAT. Copy that .dat file to your computer and open it in hex editor. Search for: BLUS31156 (it only comes up once) and change it to BLES01807. Copy the edited .dat file and replace it into the LICDIR folder.
Fourth, find the PS3_DISC.SFB and open it with ps3tools and simply change the BLUS31156 to BLES01807 **OR** open it in hex editor search for BLUS31156 (it only comes up once) and change it to BLES01807.