Can't get 2560x1080 from DVI on AMD

Hey guys, I am trying to get 2560x1080 from DVI output on AMD R7 250 to a 34" LG 34UM61.  I've tried 3 different DVI to HDMI cables but can't get more than 1920x1080. 

 

1. Amazonbasics HDMI to DVI (it has dual link-D pins but don't think it handles dual link

 

2. Buycheapcables 15 ft HDMI to DVI-D dual link cable gold 24k v. 1.4

 

3. UNMCORE Gold plated HDMI to DVI-D dual link 24+1 pin male to male HDMI

 

I looked in LG monitor manual, and it says for 2560x1080, Horizontal freq should be 66.7 and vertical freq should be 60

 

When I looked in AMG settings, I didn't see anywhere to input these?

Anyone have any suggestions? THANKS