Hola JimEvery Imperial made starting with the 1959 production year until the last one went out the door in 1966 ( I mean 1978 ) had the 413 and then a 440. If you truly have an 383 cubed engine, it is cause the original one went bye-bye.I understand that things do happen in time. Sooo, the answer to your question is: any exhaust manifold from the left hand ( aka drivers side ) from 1959 to 1966 will fit if it is from an Imperial ( 413 or 440 ). If it is an 361, 383,413, 426 wedge or 440 from an lower division of MoPar and has the center dump exhaust manifold, it to will work.If you are think this may be a good time to do an "retro-fit" and gain some quick power by using one of the HP exhaust manifolds made from 1968 to 1978 that was on GTX's, RoadRunner's, Crashielr 300's and some more, do not waste your cash on any manifold from any spec'd whatever of these car's cause they will not fit/clear your ( or any 1959-1966 ) Imperial on the left side.From the 1972 to 1978 Dodge Truck Division there is an HP center dump Exhaust Manifold. It will add more power and appear as if it was placed there by an Imperial worker in 1960. Both sides dump in the center and it will fit with out taking classes to learn how to get it to fit.Rodger & GabbyCOS----- Original Message -----From: James L BURTONTo: mailing-listSent: Wednesday, April 18, 2007 4:56 PMSubject: IML: exhaust manifold for 60 imp 383Hi everybody, Jim Burton here, looking for a exhaust manifold for 60 imp 383, the side without the heat riser gismo. Im not sure if a 413 will fit. thank you