They have a slightly larger rolling radius which means it will raise the front end slightly. I used 70's on my 05 636 and never bothered touching the front or rear ride heights. If you are trying to cut a lap record, I could understand it, but at the pace we road riders run even on a track day it will never worry you. It was good enough for 1'46"s around the Island and 54's at Broadford so it can't be too bad!
Mind you, if it's a track day tyre you want, i highly recommend the Bridgerock 002 race tyres and the Metzler Rennsports/Racetechs are both good too. The Super Corsa's are ok, but I find they scallop out quickly. Whereas the metzlers give the same grip with better wear, and the 002's just stick like nothing else!! (ezpecially the fronts!!!)

"I hate to advocate drugs, alcohol, violence or insanity to anyone, but they've always worked for me" Hunter S. Thompson.
There are really only two questions in life. 1.Which way do i go? 2.What is the lap record?