No, note that the table says "GCR Vehicle Weight", which in all cases includes the driver. So regardless of what your car actually weighs, your required cage tube size is based on the minimum weight listed in the GCR. In your case, you can use the 1700-2699 pound category tube size, since you're listed at 2600.

Quick history lesson - for many years the tube size was based on a table of under 1500, 1500-2499, and 2500 up, using vehicle weight without driver. Then SCCA started basing vehicle weights on all-up at the end of the race, including driver, in most cases by adding 180 pounds to the previous (without driver) weight. And to maintain the cage rules unchanged for existing cars, tube sizes were then to be based on listed weight less 180 pounds. SCCA also came up a completely different table for SS and IT cars, based on the presumption of bolt-together cages. This had breaks at 1500, 2200, 3000 and 4000 pounds (also based on GCR weight less 180 lbs). In the latest iteration (starting 1/1/08), all cars including SS/IT now have to meet tube sizes based on GCR weights, which include driver. And the weight breaks are now at 1700 and 2700 instead of 1500 and 2500. So the newest rules are just like they've always been for most cars, except the presumption is now a 200 lb driver instead of 180. And the SS/IT cars how are treated just like all other cars instead of having a more stringent set of requirements - this eliminates the silly situation where IT cars had to have better cages than the (usually) faster Prod and GT cars.