'Party Down South' Stars -- YEE HAW! We Want 1,400% Pay Raises

This oughta jar your preserves -- the "Party Down South" hillbillies are getting smuggier than "The Real Housewives of Beverly Hills" ... demanding a 1400% pay increase.

We're told cast members were pulling $500 each per episode for Season 1 -- but now that the show's a success, cast sources say the stars are banding together, demanding $7,500 per episode.

They have some ammo ... "PDS" has quickly become CMT's most successful program ever.

Our sources say CMT is hesitant to cough up the money, but the stars want their raises finalized before they shoot a single frame for Season 2.

We got the cast out Thursday night ... and they clearly had booze -- not bills -- on their brains.