The two valves in '94 were for two different engines. The TBI used a vacuum opertaed EGR, the CPI engine used the digital valve. You cannot mistaken these two for one another, they are totally different.
If the EGR valve fits, and the connector plugs in, chances are you have the correct one. As long as the Service light is not coming on, a smaller hole will not harm it. It will actually improve performance for that matter. For it to be carboning up fast like that, you may have a leaky regulator or injector.