http://chevyhiperformance.com/techar.../148_0306_406/ This article shows how to do a 400 sleeper motor that roars for cheap. If the sleeve was done right they work good ( ran my bbc 8200 with one). Check piston to wall to see of a light hone may still keep you in specs, it may have been too tight to start with. 400 is a good engine if done right, double check everything.