My friend Scott Cross has started to re-make dual wheel spacers for 12" rims(they work on any size tires not only 6-12 like the IH adapters). Another good thing about this type of adapter is that it won't cake up with MUD BTDT.
http://ihregistry.com/forum/messages/74/74.html?1169251245#POST84843
Scroll down to the 2 posts by Scott Cross( E-mail ihcubcadet@charter.net )
http://ihregistry.com/forum/messages/74/74.html?1169251245#POST84843
Scroll down to the 2 posts by Scott Cross( E-mail ihcubcadet@charter.net )