the MDU is a four field starter used on the R series motors. The MDY is a two field starter used on most all other V-8s automatic - manual MDU 7026, MDU 7025 (18 Jan 2008) The above information was obtained from this source http://www.carkb.com/Uwe/Forum.aspx/studebaker/4362/Starter-Designation It appears to be erroneous...