I am looking to upgrade the stock Ranchos. From what I have been reading , the Bilstein 5100s would be a decent upgrade. I tow a 33’ travel trailer (dry weight 6500 lbs) and ride feels horrible with and without travel trailer hooked. Anyone here have Bilsteins on their AT4? I did see an older post of one member installing them. What is the part number of the ones you installed? Cost of install? Was initially thinking of getting airbags but this might be better.