I have been as fast as 10.90 @ 123 with my 8.5:1 small block with a .528 purple shaft. 2700 lbs and 2.02 stock "J" heads. I know it is not the .557 in the heading but it is totally attainable with the right combination. 4:10 dana gear shfting @6200 and trap rpm of 6000. Best 1/8th mile was 6.82 @ 98mph.