I agree, more cubic inch is better, but seems it is better to get there with the bore. I think since the 530 blocks have less core shift than the earlier blocks maybe I could take the bore out further than the typical 4.375. Anyone know how far the 530 400 blocks can be bored and still have plenty of meat left in them? Can they go 4.500? 4.400? 3.91x4.500 is almost a 500ci, 498.