Rare Dodge Dart GT? Which engine is this?

Orange heads could be a good sign.

You need to pull a rocker cover and see the casting and date.
Orange or Hemi Orange if stock only says it's a 69' or under small block. My other posts state that it is a good possibility a 60's motor not 70's as others stated. The valve covers and water pump are from that era, but could of been changed.