Looked up the part numbers in the 73 parts catalog and only two numbers are listed. RW (Satellite/Charger) with 318, 340, 400 use 3466123. RW with 440 use 3466113. The 440 tip is one of the two piece resonator style tips. I think the other tip is the long style as those are the ones I have for my 74. One of the sets I have, I took off a 73/74 car myself. Others will tell you the Plymouths got the short style and Dodges (Chargers) got the long style. That is probably true for the 71/72's, but I guess when the body style (new rear valance styling) changed MA Mopar went to one tip style for both Plymouths and Dodges.