Im doing head gaskets on a 62 Dynamic 88 with a 394 in it. Im thinking it may have a cracked head because there was coolant under the valve cover and my compression check had 80 psi on two cylinders that where next to each other. All other cylinders had 140 psi for compression. The customers complaint was it would over heat all the time. He had the radiator rebuilt rebuilt and the cooling system flushed and a electric fan installed. Im posting here for any suggestions from others that have worked on an old girl like this. I have the heads being pressure tested by my local machine shop.