1973 Dart H Code value

If the parts car is good enough for ALL the steel you will need, and the 340 is the numbers engine, then I'd say $1500 +/- would be reasonable. Emphasis on ALL the steel. If the roof and structure is gone (and they are) there will be a lot of other metal bad below that... Floors, frame crossmember(s), rockers and connector parts - all would be suspect. Bad roof is bad. Bad = expensive in labor and parts.