I am thinking about upgrading the gears in my 2003 Silverado 2500HD with 35" tires but I am not sure which would be the best set-up, the 4.10, 4.56 or 5.13 set-up. I found a web-site that says the 4.10 ratio is best for gas mileage, the 4.56 ratio is closest to factory, and the 5.13 ratio has the most power. I understand that with the 35" tires, upgrading to anyone of those ratios will be better than keeping the stock 3.73 gears. I'm sure there are many others on here that have been in my shoes, so I'm trying to find out which is the best route to take. And not to sound like a complete idiot, but how many gears would I have to get? The reason I ask is because I found DANA 5.13 ring and pinion gears for $134 and both DANA 4.10 ring and pinion gears and DANA 4.56 ring pinion gears for $129 but the image shows just "one".