I went crazy trying to find a good rear to fit my truck, they're hard to find. Most Chevy truck rears were geared for pulling power (3:70's-3:90's, some 4:11). I took the easy way out. I used the stock 3:72 rears with taller tires. I swapped the 27 inch tires for the LT 30 inch tires. It made huge difference. With the 27 inch tire I was turning 2800 RPM's at 60 MPH, with the 30 inch tire I was turning less than 2000 RPM's at 70 MPH. You'll notice the difference on the highway when your engine isn't screaming to keep up with traffic, and you're saving on fuel. If you're really bent on changing the rears, you won't notice much difference between the stock rears and a 3:08. You will when you get to the 2:70's -2:90's. But, they hard to find. The cheap easy way out is taller tires.