SER have 2841/2839 runs on Modified version of LHB type rakes.
Only the braking and Collision Avert type system has been incorporated in these (not so)old but modified Rakes of the mentioned trains.
Also these types of coaches are used in AP and dakshin express in SCR. Not sure about other trains.
Things...
more... to look out for:Pls chk the Boggie numberring system; it should end with "/C" type and both the ends of a boggie will be painted a vertical line as indication of the Collision Avert technology type.
And as far as my knowledge goes only 2273/2274 Duronto is being given the New LHB version of the Non-AC Rake.