Hi i have a 05 trailblazer 4.2L 4x4 with a 4.10 rearend ratio and a friend is giving me a 3.42 rearend would that work on my jeep cuase i is pull my boat with the jeep ? Can anyone help me out plz

 

Question: How big is the boat? The 4.10 is a lower gear ratio than the 3.42 so it is better for heavy duty work. The 3.42 will give better gas mileage, but it won't pull heavy loads as well. You may also discover your speedometer is off, as well. Is your Jeep 2WD? If it's 4WD and you only change the gear ratio in one differential the Jeep will lock up in a matter of feet if you put it in 4WD. That's because one differential is trying to turn at a different rate than the other. In a 4WD vehicle both differentials need to be changed.