M52B25 iron block with sleeves?

[andrewgordnier]

Forgive me if this is a dumb question, not super familiar with these cars. I was under the impression that all non-tu blocks were iron and not sleeved, but my block appears to have sleeves in it. I have attached pictures of both what appears to be the sleeve and the stamping on my block. Thanks in advance. IMG_5076.jpg
IMG_5075.jpg

[Eric93se]

Try cleaning the interface with something gentle like wd40, scrub with an old toothbrush and see if the line goes away.

[bluptgm3]

Try cleaning the interface with something gentle like wd40, scrub with an old toothbrush and see if the line goes away.

+1^
Looks like a head gasket seal ring trace.
Unlikely an indication of liners in an iron block