O-scale track compatible with Fastrack

I’m modeling in O-scale with Fastrack and have a bridge over which I need track compatible with Fastrack but without the “ballast” (ties & rails only). Any ideas? Thanks. Mark

They make a conversion set that go from fastrack to O and then from O to fastrack again

Fastrack to “O” Transition piece # 12040:

I thought the transition piece was for FasTrack to O31, not O27?

The transition piece IS for O-31 track. However, many folks just enlarge the track ends of O27 track and shim it up to mate to O-31, same thing will work here.