General Custom head on existing driver issues

[Petrifieddoublegulp]

So close!, anyone know how I can make the head sit within the rest of the model like the original head?​

I thought that dropping it into the model with the same object name as the original head would do it, but something is kicking the whole thing out of wack in the organization of the fbx? The driver shows up just fine in CW Showroom with it's head on right, it's just when loaded in a race that he gets Decapitated! Somewhere I must be missing a link between the original head and the rest of the body that I'm not carrying over. Any insight appreciated!