What Space Shuttle era components heavily inform the design of the modern SLS?

RS-25 main engines and SRBs

The development of the Space Launch System (SLS) employed a strategy termed heritage adaptation, leveraging proven, flight-tested hardware from the retired Space Shuttle program to accelerate development and reduce initial costs for the next-generation super heavy-lift vehicle. Specifically, the SLS core design incorporates massive Solid Rocket Boosters (SRBs), which provide a significant initial thrust, directly descending from the Shuttle's SRB technology. Additionally, the powerful RS-25 main engines, which form the core thrust element of the SLS configuration, are also adapted elements originating from the Space Shuttle era. This integration allowed NASA to achieve the necessary performance benchmarks for lunar missions while leaning on decades of operational experience with these specific hardware elements.