I believe 4.77's are available for the older trooper styles and are intended for 31" tires. They were also a factory option. They wont work for us. That generation has the 10 bolt rear and ? front. When they went to the 2nd gen, they took the larger back and used it up front and slapped an even larger 12 in the rear so f and r got a size increase. thats same as ours. our only option is the 5.38 as far as I know (in the US). 5.38's used on troopers brings the gearing with 33's to about stock again and the speedometer is accurate again. So if 33's is what you want, and stock ratios is what you want, go with the 5.38's. If 31's is what you want, the 5.38's will lower your gears a little. Great for 4wheeling, acceleration, not for gas mileage, not for top speed. I still cant believe all the VXers that keep wanting 1/4 mile times faster, but dont do gears.