1972 340 challenger

I,own a 1972 340 automatic challenger with original engine and transmission.The engine is a 340 and the transmission is the torqueflite.I,know that for this year the engine was detuned and pistons and valves wher changed,what I would like to know is if there is a kit that I can purchase to make my engine 1970-1971 specifications,thank you,[email protected]