The manual highlights the specific evolution of the 737-300 compared to its predecessors:

Detailed procedures for deploying landing gear via the alternate manual system if Hydraulic System A fails.

The Boeing 737-300 Flight Crew Training Manual (FCTM) serves as the primary technical blueprint for operating the "Classic" generation of the world’s most prolific jetliner. Representing a bridge between vintage steam-gauge cockpits and modern glass automation, the 737-300 manual details the transition from the Original series to the high-bypass turbofan era. Core Manual Components