M73 Rebuild

[M73 Mike]

I've got an M73 torn apart. I've been searching online trying to find a guide to rebuilding alusil blocks. Before disassembly a leak down test showed good compression across all cylinders. But now that I have the heads off I can see a black area in the alusil coating about 1" down and approximately 1" long. It doesn't catch a finger nail, but it's defintely there.



That's the best picture I could get. It's the black mark in the middle. It's not carbon, to me in looks like a place where the silicone crystals has been scratched through and just alusil is left.

Is that a concern? Will that continue to spread if I don't do anything to address it?

The 11 other cylinders look perfect.

I would prefer to keep the bottom end together the reason for the rebuild was a bad oil leak that I have already found.

Also for the Pelican folks, I wasn't able to find a set of gaskets for rebuilding this engine. Do you have a package with all of the minor seals?