Well, whilst your success with this turbo like any other relies on the tuning of the car, be aware that this is a 500+ hp capable turbo. It flows around 65 lbs which means if your car is currently stock you are going to need to look at your fuel system. You may well need a bigger pump, you may get away with the stock fuel line and filter but you will need much larger injectors. You are then going to require something to tune the fuel delivery and get the car to idle with the additional fuel. These turbos are designed for high boost pressures and whilst they spool pretty quickly want to be pushed to at least 30 psi if possible. Your intake, intercooler setup and head all need to be in very good shape to withstand in excess of 2 bar of boost. The same goes for your rods and pistons. The stock block is good for 500 hp but only with careful tuning and 30 psi is a lot of boost for stock pistons and rods, unless you are very careful, failures can easily occur here.
Despite the fact that the turbo bolts straight up, it's still big and the Galant engine bay is far more cramped than the 1G. You may have to clock the turbo, dent the water pipe and even possibly look at different radiator options to make it fit. Too much oil pressure will also blow the seals on the turbo very quickly so you will need a much bigger oil drain than stock which means modifying the oil pan for a larger return fitting and looking at a large diameter oil return line.
Once you have addressed that and start making power, your clutch, transmission and remaining drivetrain parts are going to start hating you and may even fail. Get that sorted and I'd seriously consider better brakes and tyres unless you want to end up in a ditch or a wall.
Although turbos are described as bolt on, it unfortunately is rarely as simple as just bolting one up to get reliable 500+ hp. There is a lot of other work involved and things to consider.