I'm getting 325/80-16's which are 37's installed Friday, currently have 35's with 4.10's. Running 2000 rpm at 70. Anyone know about how much my rpm's will drop? I'm hoping to be around 2000 at 75 mph. Thanks fellas!

 

Buy a GPS and use that for the speedo. That's what i do. Never use the speedo on the dash anymore.

 

your gonna drop probably 300-500 rpms maybe. I know my changed it about 400 or so cause 37s gave me my best mileage but 35 tow a ton better. Good luck