57 and "up to" 58 models had the coaxial type power steering. >My guess is if his book only shows back to 58 then it is most likely to be >for the "after" 58 steering. Part number for the seal is 1730985 and shows >that was used from 4/6/56 to early 58 models. Interchanges recognize 1730985 as a Chrysler number only (it does exist) and the following interchange numbers: Chicago Rawhide 12350 (new NAPA) Victor 46113 (old NAPA and Carquest) National 68595 HTH