I know it goes against everything the "experts" say but I have a Clifford 4 barrel intake on the 292 in Otis ('64 C20, long box) and have never hooked up the water heat to the manifold. We live in South Dakota and don't drive him a lot in the dead of winter but in plenty of cold weather and have never had a problem. No explanation as to why but have run it for several years without a problem. For what it's worth...