Another question, I have a 120 Mercruiser head that I had boiled, checked and flattened that I'd like to use on the 153 for the summer. I have new valves, springs and seals on the shelf for this head and I was planning to use the keeper plates and shield caps from my spare engine but the plates are worn and the shield caps are cracked, or missing. I cannot find the keeper plates or shield caps online at Rock Auto, Speedway or summit for the 153, and none of the marine parts house seem to have them individually, only as part of a "valve train kit". I can't imagine that these are unique to the 153. Does anyone know what common inline 6 they would interchange with?
