Both bands are playing at the Carling Weekend and, according to reports, members of the GLC will be giving The Automatic a helping hand during their NME/Radio 1 Stage show on Saturday.
Eggsy, Adam Hussein and Maggot are all expected to join in the monstrous fun.
It won't be the first time Goldie Lookin' Chain have been involved in all-Welsh festival collaborations. In 2004 they hooked up with the Super Furry Animals at Reading and Leeds.
The Welsh rappers also play the Radio 1/NME Stage at Leeds on Friday and Reading on Saturday.