I sent a message to Rancho and received this answer.
"Thank you for contacting Rancho Suspension.
Unfortunately there is nothing listed in our catalogue for your aplication yet. Also, due the specifications on the 2013 model vs 2015, wouldn´t be the same part number for both.
For further questions or assistance, please contact technical assistance at 734-384-7804 M - F 8:30am - 5:30pm EST.
Rancho Team Member,"
So the 3500 got the new frame in 2013 and something changed on my 2015????
So I called RANCHO tech support, what a bunch of jerks. Guy said they might be the same but they don't have any data yet to support that. Said I could call RAM and check part numbers and put them on if they were the same. However he said if I had a problem with them, they would not warranty them as they were not in his catalog for my truck!
So we have a company that sells adjustable shocks that we might want to install on a fairly new truck and are to lazy to do a little leg work to check on fit!
SNOKING