I am no expert on engine no`s, maybe Q or Banshee will chime in on the date and casting no`s, but I do see in my little 'redbook' that YU is a `78 6.6 L V8 4bbl auto. engine ,was listed to have 180 hp and was supposed to come w/ 6X heads, but you already know what someone replaced those with... (78 they also came w a 6.6 L Olds engine)
