I have a 91 Grand Prix with a 3.1L V6, and I was wondering if there would be any trouble with swapping the current three gauge cluster with a six gauge cluster. Are the connections different, or will the six gauge cluster slide right in? And will it be necessary to alter the current speed, water temp., and fuel sensors? I know that I will have to replace the oil pressure sending unit, and the electrical sensor. Also, what will need to be done to insure that the tachometer works?

Any suggestions or tips would be helpful.
Thanks!