MTL - The Manga of Ten Thousand Realms - Chapter 398

The Spiritual Attainment of Minghe is a Chinese fantasy fiction containing themes of cultivation, Sages, Demons, Sorcerers, and Chinese Ancestors. Minghe, reincarnated from an IT nerd in the modern world, sets his mind to change his history and create another legend in Untainted Land. No one knows how many secrets he has or how powerful he is. What will happen in this afterlife of his? How can he pursue the power of the Origin in order to change his history? Discover all the answers in this book.

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

King of the silver screen, Fiennes Tang, passed away after years of fighting heart disease. He woke up to find himself in the body of an outdated idol male starlet. Since the heavens had given him a new opportunity, he decided to enjoy life to the fullest and reach the summit of the entertainment industry once again.

- Description from Novelupdates