There never was a '69 Dart Custom factory built with a 383, never mind the 2 bbl carb. All factory 383 BB Darts in '69 would be GTS's, 4 barrels, and the dizzy would be in the front ,if it was a BB. Small block dizzy's in the back of the block.
"4006730-31_. " , the blank is probably an "8", denoting a 318 engine.