8" Rim for our Wheelbarrow , Leaky Tube.. The Tube size reads (3.50 X 4.00 - 8) Lowe's or Home Depot sell Tubes for the Wheelbarrow, even Princess Auto or Canadian Tire.. But the nearest size readily available is (4.80 X 4.00 - 8)... What's the Difference in Size, My Concern is too much Inner Tube and the replacement won't properly expand.. Yes I could patch the existing Tube but the leak is in a bad spot..

Second option is replacing the wheel with a run flat (airless) . Cost more but it will never go flat again. I did this with mine. Harbor freight, Home Depot and Lowes (among many other places) sell them.

Inflate the tire. Cut the stem off and inject Great Stuff, low expansion foam. Push the tube in both ways so the tire fills. Will fill the tire and come out the cut hole. After expansion you have a never go flat tire for the price of the tube. Here is another example.
http://www.practicalmachinist.com/vb...3axzz3HvSZLSFn