Block Identification

[6.5L]

I got two extra blocks from before aside from my 599. There are absolutely so valley markings on them, leading me to believe they are chinese blocks. Can someone help me identify these other two blocks. One block has the numbers 12555506 stamped behind the drivers head in the block, but has F14 141 stamped in the bellhousing area. The other block has the bell housing on so I can't see the inner bellhousing numbers, but the numbers stamped behind the drivers side head on that block are stamped 1023714 1.

 

[ak diesel driver]

I've seen oem blocks with nothing in the valley

 

[6.5L]

What numbers do you judge the block off of? And are either the 141 or 506 blocks any good?

 

[ak diesel driver]

the numbers behind the head on the block are "the" numbers to use. 141 should be a non squirter block. I'd pick the one that needs the least attention

 

[Will L.]

Yeah, just pick the best of what you have by condition. As for 506- they have been the longest run and touted as best and worst. The optimizer is a 506 for example.

Pull them all apart, you might find you want to use heads from one, block from another. Until you inspect for cracks everywhere, you don't really know what you have.