Delta II is a retired expendable launch system in the Delta rocket family. It was formerly operated by Boeing, and United Launch Alliance (ULA). Delta II was launched in 9 different variants: Delta II 7320, 7326, 7420, 7425, 7426, 7920, 7925, 7920H, 7925H. The first digit stands for the 7000 or 6000-series Delta, the second digit stands for number of SRBs (can be 3, 4 or 9), the third digit, denotes an only used second stage with an Aerojet AJ10 engine and the last digit denotes the third stage: 0 indicates no third stage, 5 indicates a Payload Assist Module (PAM) stage with Star 48B solid motor, and 6 indicates a Star 37FM motor. A H (as Heavy) following the four digits denoted that the vehicle used the larger Delta III’s GEM-46 boosters. The Heavy variant could be launched only from Cape Canaveral (as Vandenberg's pad wasn't modified to handle the larger SRBs), and was retired with the closure of that launch site in 2011. The vehicle operated out of Space Launch Complex 17A and 17B at Cape Canaveral Air Force Station and Space Launch Complex 2-W at Vandenberg Air Force Base.

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

To download each variant of Delta II, go to the "Files" section.

Also Don’t forget to download the flags for Ariane 5 in the "Files" section.

Here are my other projects.

Delta II 7320

Delta II 7420

Delta II 7920

Delta II 7920H

Delta XLT(-C)

Delta-K

GEM 40, GEM 46

Delta II 7320
T-0:00:01 - Main Engine Ignition
T-0:00:00 - Solid Rocket Motors Ignition
T-0:00:00 - Lift Off
T+0:01:12 - Solid Rocket Motors Jettison
T+0:02:34 - Main Engine Cut Off
T+0:02:38 - First Stage Separation
T+0:02:42 - Second Engine Ignition
T+0:02:57 - Fairing Deploy

Delta II 7420
T-0:00:01 - Main Engine Ignition
T-0:00:00 - Solid Rocket Motors Ignition
T-0:00:00 - Lift Off
T+0:01:12 - Solid Rocket Motors Jettison
T+0:02:34 - Main Engine Cut Off
T+0:02:38 - First Stage Separation
T+0:02:42 - Second Engine Ignition
T+0:02:57 - Fairing Deploy

Delta II 7920
T-0:00:01 - Main Engine Ignition
T-0:00:00 - Ground-lit Solid Rocket Motors Ignition
T-0:00:00 - Lift Off
T+0:01:00 - Air-lit Solid Rocket Motors Ignition
T+0:01:12 - Ground-lit Solid Rocket Motors Jettison
T+0:02:06 - Air-lit Solid Rocket Motors Jettison
T+0:02:34 - Main Engine Cut Off
T+0:02:38 - First Stage Separation
T+0:02:42 - Second Engine Ignition
T+0:02:52 - Fairing Deploy

Delta II 7920H
T-0:00:01 - Main Engine Ignition
T-0:00:00 - Ground-lit Solid Rocket Motors Ignition
T-0:00:00 - Lift Off
T+0:01:08 - Air-lit Solid Rocket Motors Ignition
T+0:01:20 - Ground-lit Solid Rocket Motors Jettison
T+0:02:22 - Air-lit Solid Rocket Motors Jettison
T+0:02:34 - Main Engine Cut Off
T+0:02:38 - First Stage Separation
T+0:02:42 - Second Engine Ignition
T+0:02:52 - Fairing Deploy

Calculated with full thrust.