Engine

[Charles P]

Hi

Those cracks round the centre stud are supposedly pretty common, and are possibly due in part to the stress when having liners fitted.  My own engine has two fine cracks here, but it doesn't seem to prevent the gasket from sealing OK with no special measures needed. I wouldn't tune it up and go racing though.

Of more concern would be what appears to be quite deep pitting on the block upper face, which ought to be refaced flat.  This may then require the addition of a metal shim plate between block and crankcase so that the piston crowns are still clear of the head. You will have to balance the cost of this against sourcing a better block.

Agreed. 
From what I can see of the valve seat that block has led a hard life.
I’d start with another block, but others will champion the reuse angle I’m sure

Charles