[ursus]

I have yet to come across a diamond "A" block but have been through a number of diamond "B" blocks that were beyond restoration because of casting flaws, mainly core shifts that resulted in thin walls in the upper deck, valve pockets, and the roof of the valve chamber. Cracks running everywhere. Try to pin a crack and new ones form at the periphery. The original Ford produced "B" blocks have their issues as well. Since most all of my "B" engines spent their lives in an industrial application it is possible that they were not always well maintained. All told, I found one repairable diamond "B" block out of 7 that were hot-tanked and magnefluxed - not a good record.

As far as the diamond "B" blocks are concerned, my take is that their claimed superiority is a myth.