The cover was changed in when the Camaros went over to OBDII and needed an extra sensor to pick up misfires, It is possible that some late 95s came with the new cover.

 

So what am i gonna have to change to my 94 z to make it LT4 adaptable?

 

The LT4 heavy duty timing set should fit under the 95-96 timing cover. There were 3 timing cover versions. The first version 92-94 won't allow the LT4 timing set. There is some confusion as to when the different covers were used, because the F cars were always one year behind the Corvette and B bodies with updates.
This link may help out:
http://www.dougrippie.com/
look in the "engine components" section