Hi Ciao
On the Chevy Pattern 12 the oil filter is located horizontally in the left frame rail and is attached by combination of flex rubber line and steel pipe. The same location and system was used on the early Chevy Pattern 13s
http://www.canadianmilitarypattern.c...STORATION.html see bottom picture, you can see the oil filter at the lower left of the picture showing the open gear box.
Location was later changed on the Pattern 13s to a larger filter mounted on a bracket vertically and the rear of the intake and exhaust manifold.
As to the artic kit really need to know Ford or Chevy. I have the cold weather modifications manual for the late Chevy Pattern 13s. Which I can scan and post.
Cheers Phil