With a stock Ram you'll be hard pressed to have most 5th wheels level when hitched up. JMO and it's what I did would be to get just a leveling kit installed. 2" springs will make it look level. You should have about 3" difference between the front and rear fender heights. After you hitch up the 5er the rear will drop about 2+". You will need air bags to re-level the truck.
I have a 2500 and if you have a Cummins in yours then the payload is fairly low. My 5er's pin is only 1800lbs. That and the gear we put in the back of the truck drops the rear about 2". That makes the headlights shine upwards. I added airbags to get the rear up a bit. With that being said my 5er runs nse high about 1-1/2" or so. Before the level kit was added the truck and 5er were darn near perfectly level with no bags, just the stock suspension.
It still tows just fine but when staying for a quick one nighter I need to unhitch or the 5er's too high to be comfortable in.
Not all 5ers are created equal so some premeasuring will help.
If you do have the Cummins then you'll be limited to lighter pin weight 5th wheels. Usually mid profile. Those tend to not be as high.
A little research is key.
