I have been over heating reciently in which has never happened before. I just changed the manifolds and when I did I poured out a ton of sand. I think some sand is in the block so I am going to flush it out. I don't run a termostat and have never run hotter than 120 degrees in the past. I am thinking of droping in a 160 temostat after flushing the block to slow the flow of water to pick up more heat. Any other suggestions as things to look for?