The bars are 2.3"H x 2.3"W x 22.5"D ( according to weber's site)
Many buy aftermarket stainless steel Flavorizer Bars and they last alot longer than the porcelain coated bars that Weber sells.
I bought this set a couple of months ago for a Silver C and they fit fine. There are a lot of aftermarket flav bars, of varying thickness of stainless steel. This set was on the lower cost side.
Made of porcelain-enameled steel, the Weber Flavorizer Bars come in a set of five, divert grease to reduce flare-ups, and catch drippings to add flavor.
www.weber.com
And a link to the parts diagram for a 00/01 Silver C