Not all leaks in an engine can be detected by magnafluxing for cracks. In these pics it can be seen that the heads are leaking above the valve seats around the valve guides. This is why we always pressure test cylinder heads even if we don’t find any visual cracks during magnafluxing. New valve guides will be in order for these 454 big block Chevy cylinder heads.
Motor Mission Machine & Radiator 5435 Desert Point Dr. Las Vegas, Nv. 89118 Phone: (702) 649-2366 or (702) 649-0648 Fax: (702) 649-4133 www.MotorMission.com Facebook.com/MotorMission