EVO III in stock 91 GS turbo

[Goat Blower]

The only things you'll need to run anything over stock boost with that turbo is bigger injectors, which in turn requires some sort of fuel tuning device, and a larger fuel pump. You can just drop it in if you're only going to run stock boost, which will still be quite a jump in power from your old setup. If you feel a 16G would be laggy, you should just buy a Moostang instead. Lag=power.