Is your mod an esp? You need to use FNVedit to make it an esm. That should fix this issue and make the body match the head.
To make your mod an esm, open FNVedit, click the + next to your mod, and select File Header. Then on the right side right click in the open slot next to Record Flags, and say Edit. Click OK if it asks 'Are you sure you want to edit this?!?' then check the box next to ESM. Click OK and close and save your mod. Then change the file extension to .esm.
That should fix your skin issue, however, you cannot edit an ESM file in the GECK, so make sure you dont have any other changes that need doing first.
You can, however, always change it back. Just change the extension back to esp, and uncheck the ESM box and save.
Hopefully this helps.

Alexander J. Velicky