I'm thinking about picking up a 4 bolt main 350 that has been bored .30 over. The block and everthing seems ok except for one cylinder. The valve spring broke allowing the valve to fall down into the cylinder and make contact with the piston. Even though that cylinder was not working properly, the engine still ran great. Pics of the piston are below. Also I would guess that since the valve spring broke I need to go through the heads. Would it be cheaper to rebuild the heads or get a set of new ones? I found these heads on summit. Would they be good for a mudder/DD? How about this for an intake? I'm sure the cam got trashed when the valve spring broke. How about this for a replacement cam? Here are some pics of the piston.