Certainly don't think you'd fit a diverted GC HST or Hull/GC 180 in there anymore- though P6 is unaffected. Not sure how long a set they could take before- could they fit an 8 car 317 or 365? Matters little, in normal service it's mainly 2 and 3 car car 170s, with one or two four-car 317 services- all of which should still comfortably fit.