sure grip install

Hey FABO
I have a low mileagae 489 case 3:55 center section I am getting ready to install in the Duster. It is a non sure grip unit though. What kind of hassle would there be to install a suregrip unit? Its out of the car, very tight unit. Ive never been into the gears before and was wondering if anyone could give me some insight. I have not bought the suregrip unit yet.

Thanks guys

Floyd