Yip" i done it last year, needed= barrell [ 171cc stamped on side] matching head, piston/ pin/ and smal lend bearing, the small ends and pin are not interchangable, exhaust is same , carb jets need to change main to 150. pilot to 30 , it may be 30 in yours older dt125 was20, its a case of see how she runs..
Oh gaskets are bigger, base head,,