Overload, my tractor has the same toggle switch you describe. I thought that you must have skid steer tires (see my previous post). I looked them up and did the math (inches x 24.5 (the number of millimeters/inch) x 3.1417 (pi) and came up with the 3112 millimeter circumference. Based on the chart in the tn75 operators manual is where I came up with the final numbers. I didn't find a tire that would fit your front rims that would be tall enough to work. Do you require 4wd a lot? If not maybe you should let sleeping dogs lie?? Your rear tires are so large that they went past the chart in my manual....but it is a linear relationship and I feel confident that by extending the graph, I gave you the right numbers. I asked the NH dealership if there was any change in tire specs b/w 2002 and 2005 and they said no. If you want me to scan and send you the pages out of my manual, I will be glad to do that. Just use the message function on the board to send me your email address. To me, it sounds like you either have to 1. get different rear rims and tires 2. somehow find a larger 19.5 inch tire 3. find another NH compatible front rim that will let you upsize the front tires 4. just live with a new set of front tires and minimize 4wd usage. There may be others who are more experienced with this to give you more sage advice. Let me know if you want me to scan and forward those pages.