Differences between early/late M42 blocks? Main bearing Q

[Jaredmac11]

I noticed that one main bearing looks completely different from the rest.  Could anyone verify if this main cap bearing is different from the other 4 from the factory?

https://m.imgur.com/gallery/jBSpY

The main cap, bearing and the block at this one cap (main thrust bearing) all look different from the others.  The main thrust bearing looks fine, but I haven't tested clearances or specification yet.

I'm wondering if I'll need a new block or not.

If I do go with a new block, I wonder if I can use the early m42 block?  I have one available to me for low cost.  I want to utilize the late intake, knock sensors, and timing case (all slight improvements over the early m42)

I'm just not sure if the block is a 1:1 swap in that regard.


Thanks for any input.