yeah,a gear install is something your not going to want to tackle yourself most likely.on average a good price on a gear install is 300-400 bucks and then about 200 for the gears and you'll need the install kit.so plan to spend a good 600-700 bucks on the project.depending on your future plans for the car and taking other things in to account you would need to make the decision on which ones based on that.if your money is semi tight and you may want a supercharger but its not in the very near future i would go with 4.10s,if your going supercharged then maybe 3.55s or 3.73 at most.plus if your going to just do gears now and have some fun with it then later on down the road when you go to actually build the rear you can make a gear change then since your going to be going to 31 spline axles and posi unit im sure so its all going to be taken apart anyway.just think it out before doing it.