I am not showing a 3T50 axle code double check your Label.
Here are the vin id codes for axle on your vehicle if in fact you did read the number incorrect and your new number matches one of these then heres the answer if not please reply
You are going to have an 8.8 or 9 inch inch ring gear This is just a guess the 3 50 on your last post is the 3.50 ratio in a 9 inch. Look on the differential cover there should be a tag that looks like this. Double check the code on the door as well it should look similar to this