Nos, never built 318 (340) X block. Still in its original factory orange with inspection marks. Bore is 3.860. Cast 4/30/1979. 4104230-318-5
$3300 obo.
I've had this block for 10 years and time for a new home. If you have been thinking about a turbo, nitrous, or supercharging a small block, this might be a block to take a look at. Included a couple of pictures from the small block book that might help answer questions. Per text it can handle 2hp/cubic inch (see second paragraph under design and development).
Located in Sunnyvale CA (about 1 hour south of San Francisco). Hoping for local in person sale but crating and shipping might be possible.