im using the stock screws, being a copper base... the stock screws were strong enough to tap the holes.
im  running them at 250mhz still, but its alot more stable and drawing alot less from the usb hub (probably why its stable now)

once i get a few days out of the stick stable.. ill ramp up the voltage a little and try 275.  i seem to have lost the silicone lottery a little, as this stick needs more volts that others have mentioned to get is stable

at least i now have the cooling to keep the voltage under control

will post updates as and when they arrive

ps, might use the old cooler on the back of the stick using some of those thick heat pads you usually get on gfx card ram   just need to find longer screws with the same thread