That is exactly what my 1987 Dodge D150 had. I bought it new off the lot. Basic truck 225 slant six 4-speed. No air or rear bumper. Had them install dealer add on AC and bumper. I liked that truck. I think it had 330k on it when I got rid of it.
Similar to mine that I pictured, except mine are flat on the bottom with a rubber gasket and has a center stud and load spread spacer to tighten it down from underneath.Hardware and home improvement stores sell these plugs which don't look too bad?View attachment 134874