The Crack is on the manifold side of the block in the center section. it is on the front side of what is a raised ares that looks like something would screw into it. I think it could be a second position for the throttle linkage pivot or the pivot point, not sure on this block.It is a very fine crack and circles this raised area. About three inches long. Tthe shop found it when I had it magna fluxed
Does it leak?
