You will need to double check the relevant backround info that site uses first because I don't think it's 100% on the money all the time. If you do find something wrong you can correct it yourself if you wish under a 'custom'. But in all reality the end result is a calculation and not real world. It should be close but don't put too much into the outcome.
I recall from test reports that the 1098, geared stock, routinely ran into a hard rev limiter at about 174 mph. Unless you gear way up to keep the engine revs down, they may limit top speed. I've never tested this...
