Hello i own a machine shop, and need help on telling the difference on a CA emissions and a Fed emissions CYLINDER HEAD.
thanks.

Not that I can necessarily help you with the answer, but I bet the answer depends on the year of the engine.

Here are some differences between the '94 California head and '94 US head:
Calif head has one distributor adjust (timing) bolt, US head has two bolts
Calif throttle body has air hose from air tube. US has TB air hose from cylinder head and no air tube.
Calif engine has VSV for fuel pressure control. US does not. (head mounted?)

'99 heads:
Calif has air hose (air assist system) attached to a cylinder head port. No hose in US head
No distributor in either head
No VSV for fuel pressure control AFAIK