I know it's not exactly the way you wanted to go, but what about a atomic long engine (with warranty!) All the R&D's done, brad's done heaps of them, then just concentrate on the bolt on's. answer to the blocks, they are all the same other than the dipstick hole- BA's & BF's at the frount, FG's at the rear, so if you get the wrong block redrill it before you assemble it. I would assume the newer the engine the less corrosion. But get it checked anyway, easier now than after a split bore!