Is this a web crack?

[gmc64sub]

I just replaced my old rear main seal with the new two piece type. I did notice a possible web crack while I had the pan off. To see the photo, you have to look in my webshots "suburban diesel conversion" album:
http://community.webshots.com/user/rst64

[450]

Hard to tell with the photo....mine were alongside where the outermost main bolt sank into the block web...running the same direction as the bolt...when the crank ripped out of it,...it was along the same lines....just bigger cracks by then...did the oil seep out after you cleaned it and let it sit?...it would verify a crack.

[450]

Hard to tell with the photo....mine were alongside where the outermost main bolt sank into the block web...running the same direction as the bolt...when the crank ripped out of it,...it was along the same lines....just bigger cracks by then...did the oil seep out after you cleaned it and let it sit?...it would verify a crack.

[odee]

I've had pretty good luck with spraying the mains with either then waiting a minute for it to dry then you can see the cracks. Hopefully it isn't I have a few here at my shop that are cracked.