Thanks for the additional information. I want tires of two different diameters so I can switch them from front to back for different final gear ratio effects. I've got 2.75 and 2.47 ford rearend gears, so with the two different size tires that gives me 4 different final gear ratios. We tried this on the Stude, but with the B motor and the speed we ran it wasn't really necessary, yet.
With the smaller F motor that I finally want to run I think a selection of final gear ratios will be more critical.
I think I'm just going to have to save up and get the better tires to begin with as I eventually hope to be in the 225 to 250 mph range.
I appreciate all the thoughts on this though.
c ya, Sum