Skylab facilities modifications at KSC
The facilities required at KSC to support Skylab were largely those facilities used by Apollo, modified for Skylab's particular needs. The one exception is the series of modifications to permit launching a Saturn IB from Complex 39. This new capability not only supported Skylab, but also supports the upcoming Apollo Soyuz, and any further S-IB launches that might be undertaken.
Phillips, J. D.↗