Thanks Jim and Tony
That is a good site to know about
Tony .spot on .just went and had a better look and it is 6049 on the head
Also had a look in the other spots you showed .Picture of locations very helpful
Nothing on the gearbox bellhousing .I did however find the number c11a-6520-c2 on the inlet manifold . I think it is only a part number though ?
looking around the cab i also found another b number on the front window sill on the passenger side .Would this also be a quality control inspectors number ?