Titan IV is a retired expendable launch system in the Titan rocket family. It was manufactured by Lockheed Martin and operated by United States Air Force. Titan IV was launched in 2 different variants: Titan IVA and Titan IVB. Each A and B variants had subvariants denoting mainly the third stage. The Titan 401 had as a third stage Centaur-T with dual RL-10 engines. The Titan 402 had Inertial Upper Stage. The Titan 403, 404 and 405 did not have third stage. The vehicle operated out of Space Launch Complex 40 and 41 at Cape Canaveral Air Force Station and Space Launch Complex 4-E at Vandenberg Air Force Base.

I recommend turning on "Advanced tweakables" in KSP settings.

To download each variant of Titan IV, go to the "Files" section.

Also Don’t forget to download the flags for Titan IV in the "Files" section.

Here are my other projects.

Titan IVA 401, 402, 403