As far as I know with these dashes, there are no switches to change them from I6 to V8 or vice versa.
Also, you will need to fit an Oil pressure sensor, instead of the standard Oil pressure switch that is fitted.
Apart from that, It should work nicely !!!
(I dont have My EA workshop manual with me at the moment, so I dont know If the plugs are different, or extra wires need to be connected, but as far as Im aware, the only concern is the Oil Pressure sensor - Without it, Your Oil Pressure will Read either Full pressure, or No Pressure.