Yes,the 65 Polara is a C body.
The C body 4 speed pedals,floor hump,linkage,Z bar,and trans crossmember do not interchange with B body.
Shifter is C body only and depends if it was console or bench.The Inland C body shifter is a rare piece,but often worn out.
Bellhousing will work since it is not a body related part.
The crossmember will work on 65 to 68 C body with 3 speed or four speed manual transmissions.
There are members of the following forums that are always looking for 4 speed C body schtuff..
http://www.cbodydrydock.com/news.phphttp://www.moparfins.com/forum/default.asphttp://www.forcbodiesonly.com/http://cbodyhomeport.yuku.com/