Originally Posted by BroadPwns
Keep in mind that the main reason behind delidding is replacing a TIM for something the most efficient and durable, paste will require changing after a "while". Reconsider using liquid metal.
I'd use LM too but I've seen results within a few C of LM with normal paste. As long as you know it won't last 5 years and you don't seal it up, there's really not a downside to just using paste.
It will still last a very long time.