I don't think this will fix the problem of the memory temps rising.  The reason i say this is because your gpu temps are fine.  You'll still run into the thermal temps on the memory rising over time as the thermal pads on the memory degrade over time.  just make sure you have good thermal pads when you replace them next.

try the thermal pads that came with your blocks... if values are bad for memory, try and find better thermal pads.
you can always source thermal pads from digikey and such.