I tore down my LA 360 for a rebuild. when taking off the timing case cover ,I found what looks like a bunch of cracks. they are located right behind the water pump. Where the water pump blades would be.

Not sure if they are casting lines or not. There are allot of them, and there are just as many on the back side of the cover at the same spot.

But both sides are not identical . Have you ever seen this before. I looked at other covers and did not see any of these lines.

I have a few that look like what you are describing. One is on the engine in my Dakota. It should be fine.

Only when there has been ice in the pump, engine was over half frozen. We left the truck outside after changing heatercore and just refilled with water to check for leaks. We ended up having to replace radiator, water pump, timing cover and the new heater core.

Almost if not all that I've ever seen have had the cracks that you are talking about The ones behind the pump I media blast & fill with epoxy Sand it smooth I do this to help water flow & to keep it from corroding of course not all that I've had dealings with got this treatment & the only real failure that I've ever seen really in any was corrosion at the block around The cracks don't seem to affect anything

I saw a 340 once that the cam bolt backed out on. It did more than crack the cover tho... Filled the pan with water. We thought at first it had pooched a head gasket and were in the process of tearing it down. While taking off the fan belt we discovered that the fan was stuck. Once we removed the water pump to see why that was, there was the head of the cam bolt in plain sight.

Kevin

Never seen one cracked. But on my small block, Corrosion ate it's way right through the timing cover water jacket on the driver's side!!