How does a 1984 Corvette 4 plus 3 transmission work?

The 1984 Corvette's 4+3 transmission is a hybrid system that combines a standard four-speed manual transmission with an additional three-speed overdrive unit, allowing for a total of seven gear ratiOS. The driver operates the four-speed manually, while the overdrive can be engaged by a switch on the gear shifter, facilitating smoother highway driving and improved fuel efficiency. This setup effectively allows for better performance and versatility, optimizing the engine's power delivery across various speeds. The system was designed to enhance the driving experience while maintaining the classic feel of a manual transmission.