The engine in my newest project Vair has a code of XXZ. It looks like a 164 service block for car or truck (or Lakewood) use. Any ideas?? - Caveman Pete Pete you are hallucinating because you are up at 4:30 in the morning! XXX is a replacement 145 case and Z is an early PG case. Maybe the stamper put a Z where the 3rd X went. Clark Hartzel