The comment about a block sitting around for months before being assembled into an engine shows a woeful lack of understanding about how casting and machining is done (or at least was, a few decades ago). A "green" casting was usually left out in the weather for a year or more to "season"- - - -undergo lots of heating and cooling cycles so the internal stresses from the casting process could relieve themselves. Then, and only then was the finish machining done. In the mid-1980s when thinwall casting became the accepted practice, that process was abandoned, and parts were machined and assembled shortly after leaving the foundry. About that time, automatic transmission pump assemblies started giving problems. If a pump was disassembled and left on the bench for a few days, the halves would warp and create pressure leaks when the transmission was reassembled. We were cautioned by factory service school instructors to disassemble, clean and reassemble pumps quickly so they wouldn't have a chance to warp.
Jerry
