64 Dart GT 4 Speed Manual--Oil Pressure Sensor?

http://www.napaonline.com/Search/Detail.aspx?A=MPENS6571SB_0165506720&An=599001+101970+50056+2056018

You can usually find these NOS as well without much problem.

http://cgi.ebay.com/ebaymotors/62-63-64-65-66-67-68-69-70-71-78-NOS-MoPar-BACK-UP-SWIT-/150298048318?cmd=ViewItem&pt=Motorcycles_Parts_Accessories&hash=item22fe76373e