they actully change the heads on this buildup too. You can use better SBO heads or you can use BBO heads on it. BUT as with all olds motors the heads and specificly the exhaust side of the head are a weak point. But ya switching from a SBO to a BBO is one of the easiest swaps you will ever do as everything bolts right up including the frame and motor mounts.Philip said:The block used with the 350 diesel was the only strong part of the engine. The heads and fuel delivery were awful. It seems like it would be easier to just drop a 455 in and save a bunch of money.