radeon rx 460

so I don't really know whats going on but I've been trying to get my Sony 3D Display to output 240hz to use as my monitor. The problem is, is that I have an HDMI 2.0 and a Radeon RX 460, but when I go into my adapter settings, it doesn't show me hz over 60.

My setup: Asus 970 Pro Gaming/Aura MSI RX 480 Armour 4GB Corsair Dominator Platinum DDR3 1866MHz (4x4GB) I'm looking to replace the thermal pads on all components with Fujipoly Ultra Extreme, as in NB, VRM's, SB, etc... Problem is I don't know the best thickness for each of these components...