Just bought a 34' 5th wheel it weights 10,000lbs. Needless to say my truck is really slow in the mountains. My truck is 95 f250 powerstroke stock other than 3" downpipe. I have 35" tires and 3.54 gears with a five speed. What ring and pinion would you guys recommend?

 

Im running 4.10s and think they are great for towing

 

My truck would only go 35 mph up a 3 mile 6% grade. Will changing gear ratio help pulling in the mountains.

 

Yes, tremendously, but on the flats, higher r's and lower mpg.

 

What axles should I have?

 

It is only going to help if at your 35 mph you are between gears. You will shift earlier when accelerating. That is all. Changing gears will give you no more power. More power is what you are looking for.