I've launched an Apollo CSM from a Titan IIIE*, but chose to use a Poodle SM engine so I wouldn't have to deal with the fairing; otherwise the engine catches on the decoupler and explodes when it's staged. Maybe you could adapt the Saturn-style fairing to work but I thought it'd look funny. Works well for LKO. *not the same as FASA's built-in Voyager 2 booster, which claims to be a IIIE. IIRC I added a Centaur upper stage (present on the real Voyager) and used the SRBs labeled for Titan IIIE use, plus it looks like the Titan's first-stage engines are turned 90 degrees from where they should be.
