I cant really be sure if this Imperial was originally designed to have these resonators installed or not because this car had been restored appx. 25 years ago. Does anyone know if these were optional or factory installed?
The 1960 Imperial exhaust system is shown in detail in the 1960 Chrysler & Imperial Shop Manual. See http://www.imperialclub.com/Yr/1960/FSM/html/11-004.htm on our club's website.
And yes, you do need (and want!) the resonators (labelled as "mufflers" in the above-referenced diagram).