1999, 3500 dodge diesel six speed 4x4
i have just bought a truck it is suppose to have 3.55 in it but it turns to many rpm's even at 70. iwant 3.55 or at least 3.73 in it. is that possible . how much would the cost be. all i pull is a horse trailer. and the rest of the time nothing. i have another truck and its a five speed with 3.55 and gets awsome milage. i need sum help with my issues. i want my new truck to get better milage. all i want it to do is run 75 at bout 2000 rpm or so. thank u