Go to my mymopar.com
-> parts books -> '72
Download that. it might cover two model years - that's OK.
Find the illustrated parts drawing - I think under Fuel system, but dont recall for sure
Then take the section number and look though the numerical listing for that.
Off the top of my head the differneces are in the intermediate rod and the bell cranks,
the bottom rod and lever IIRC are different between 904 and 727