I'm gonna be performing a cam swap on my 2001 ws6 and cant clearly see any of the identification numbers on the back of the motor or near the oil filter. So my question is do the numbers on the block behind the timing chain cover mean anything?

 

Appears you have a LS1 block.

 

Almost looks like a crack in the lower right there by the oil pump...

 

I saw it too, though it looks more like a casting irregularity or shallow "crease" rather than an actual crack.