Jim,
I thought that the old bias tires were about 29 inches as well. What I mean is that when the truck was built only bias tires were used and I think the stance was taller. Now I may be wrong but you really got me to thinking because I just put on some new Coker wide white radials. I need to check the size and see, but I think my new tred is shorter then the origional bias tires.
Cliff59