has anyone heard of these tires? I've been searching the web and can't seem to find anything on these.

No info here either other than it is a Japanese brand and they make performance automobile tires.

http://www.tirepros.com/product.asp?catID=T&pID=11197&page=1

http://search.ebay.com/capitol-negotiator-tires_W0QQfnuZ1

All I could find is above. There are a few sites with trucks with 'em. Here is one.

http://www.stevesspeed.com/5015681987/truckphotos.html