That is the air intake grill I was referring to, but I don't think it was connected to the air cleaner. I think it was merely to allow more air under the hood. Donaldson came out with the first way to separate water with their water separators that came out in the early 70's.
http://www.donaldsontoolbox.com.au/tech-talk/water-your-intake-system/The one we referred to as the dinosaur head worked the best because it gave you a kind of ram air effect. Whoever, when I was in a heavy snow, I had to put one of the round ones on because the dinosaur head would plug up with snow.
I hope this doesn't get me banned from the site, but I just got through buying a cabover International like I bought in September 1968 when I totaled my GMC. If you scroll through the pictures, it shows an air cleaner that I think would have been similar to the GMC. Only difference is, the GMC would have probably had what we called a hat over the top of it to keep the water out.
http://www.ebay.com/itm/1963-International-Emeryville-/121554371167?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=Qc6G2CA6dt79YZR5sPUYJARqa3g%253D&orig_cvip=true&rt=nc
Also, the picture shows a pretty good picture of what could have very been an original seat in the GMC. I drove a seat like that for about a half a million miles until I finally bought an air ride seat.
Unless you are restoring your 860 to be absolutely original, the dry air cleaner is the only way to go. By the mid 70's, oil bath air cleaners were obsolete.
