I just got my 4.10's today but I dont know if I should have ordered a carrier also. I have no idea what gears are in my rear end. I know it has to be either 3.07 or 3.55; but isnt the break for a new carrier to fit 4.10's at 3.55 anyways? If so I will need a new carrier no matter what gear it has, but I dont know for sure; thats why im asking. Also what is the sure way to tell what gear I have? I jacked up one wheel and my driveshaft only spun 1.5 +- .1 or 2 times per every time the tire went a full rotation. Anyways help me out; I am ready to get these gears in.