If you can find a 292 core engine to build, call Alan Holmes at Lincoln County Auto Parts in Fayetteville Tennessee about doing the machine work and assembly. He's been grinding crankshafts for me since the mid-1980's, and he's almost, but not quite as picky as I am about accurate tolerances and doing the job right the first time! He won't put the vacuum cleaner into your pocket nearly as deep as Jasper will, and if you get a salvage yard core engine, it will come with all the sheet metal and other accessories that a rebuilder's engine won't have.
Jerry