My last all al Hemi grew over .020 during warm-up (505" KB). Due to the large growth, I felt I had to check the valves much more often. It didn't want to start much under 55 degrees. And I had to wait for it to fully warm up before I jumped on it much. On the street, the cooling system HAS to be up to the task. So, after living with the small, but numerous issues with the aluminum block, I went iron this time and am happy I did. (540" World)