Ian, if you are referring to UK Class 158 DMU's, they'd probably fit right in with US "HO". IIRC, British rolling stock is about 8'6" wide as opposed to US 10'6". 102"/76x87=117", while 10'6" is 126". The only place you might have a problem is length, if the cars are 80 ft. or longer. An 85' OO car would be 97' in HO!