Not on the highway.

 

I also recommend talking to Puddydad about doing your differential rebuild. He knows his stuff and does excellent work. I went with the 4.56 ratio gears and yes overall you can actually get better gas mileage with the higher ratio gear because you can shift into higher gears sooner around town to lower the RPM (and fuel usage). I can now use 6th gear at 53 MPH without lugging the engine, which was impossible with the 4.10's. Highway mileage will of course be slightly less but around town more than makes up for it...so better fuel economy per tank with combined city and highway mileage (as is my case).

 

Another vote 4 Puddydad!!!!

He builds a great diff! I 4.77's