There is a problem with the built in interiors with the new engine specs. Basically the existing one doesn't shovel on coal fast enough. S&C includes 44090:55101, TC3 44090:[FONT=Helvetica, Arial, sans-serif]55012 either will work.[/FONT]
I understand that 44090:55012 comes with the Black 5 in TC3 which was a later update available from the TC3 website.
Other than that you'll need to dig around for a suitable interior, unless you can live with DCC mode in which case the old default interior will do fine.