Rocket companies hope to repurpose Saturn 5 engines, Spaceflight Now
"Dynetics and Pratt & Whitney Rocketdyne announced Wednesday they are teaming up to resurrect the Saturn 5 rocket's mighty F-1 engine to power NASA's planned heavy-lift launch vehicle, saying the Apollo-era engine will offer significantly more performance than solid-fueled boosters currently under development."
NASA Will Explore F-1 Upgrade For Heavy Lifter, Aviation Week
"The powerful rocket engine developed in the 1960s to launch the first men to the Moon could be reprised in the 2020s as the powerplant for strap-on boosters that NASA hopes to use in heavy-lift human missions to Mars."