Pontiac Repair: Raising a vehicle via larger tires, stock tires, spedometer

Question
I have a 99 Pontiac Grand Am and I want to raise it up a little.  The stock tires are 225/50/R16 and I want to put on 215/60/R16's, which are about 3/4 inch taller.  My question is this:  since the newer tires would be 5% larger than the stock, a website I saw said that anything over 3% could impact my brake system and I may need to get my gear ratio's adjusted.  What are your thoughts on this in general?  Thank you.

Answer
Not only will you throw your ABS for a loop because the computer is programmed for only a set rolling rate from the tires but you will also throw off the speed sensor which affects the spedometer and shift points and so forth. There is a possibility that the computer can be reprogrammed for the tire size you want to use though. Check with the local dealer they will be your best bet.