I recently bought a 5.0 block out of a 97 GT. I have a 89 GT as well. I am going to have the block bored out. I have been told not to go more than 30 or 40 over. We are aiming to have a 450 whp car when we get done. So how much should I bore out the cylinders and not have to worry about them being too thin and maybe cracking under a heavy load.