I dont think you guys ever used an airless shot cabinet before...or ever tore down a small block Ford with the small pressed plugs and pipe plugs in the oil passages. If Chrysler says dont, I'll tell them they're wrong too...Their performance guys say otherwise. At least it's implied the plugs were removed prior to cleaning. MP p/n P5249704 "Mopar Engines" has this in bold.."Caution: the oil passage to the filter at the side of the block is a drilled hole.The output oil to the filter and the return oil from the filter are seperated by a pressed in plug. Be sure this plug is pressed into the pre-drilled hole until it bottoms out solidly." If they are pressing one in, I'dtake it to mean one was removed fromt he core block. The more recent Big Inch Mopar Small Blocks by Jim Szilagyi says "...the engine was completely disassembled and cleaned. All of the filing and moddifications got the block dirty, and it needed cleaning before final assembly." The first picture in the next section on fianl assembly is the small plug, and is captionned "The small cup plug was installed in the oil galley just above the oil pump. This plug is easy to forget, but it forces the oil to go thru the filter." Those are references I can find quick. I have found, as I said, two plugs stacked on on top of the other, because the previous builder missed it. I also found black nasty goo trapped there. No black nasty goos for my engines!