1972 street strip swinger

make sure you clean the engine deck surface really good around the head locating pins. in the picture it looks like you cleaned the deck but have some trash around the dowel pins. I like to use scotch brite on a 90* angle die grinder at low speeds. then clean with lint free rag and rubbing alcohol prior to assemble but you could still do that if you tape off the lifter valley and point an air gun at the surface while you clean.