Assuming you referring a "sedan" as a 4-door, all 4-door Darts were "post" cars, they weren't available as a hardtop like its larger brothers.
8500
HK Holden vehicles were manufactured between 1968 and 1971. Two varieties were available - sedans and wagons. Other lines of Holden vehicles were made as late as 1984.
Dodge
1968 Dodge Charger
Manufactured in 1968
The Dodge Charger had a new design in 1968. This 1968 Dodge Charger included hidden headlight grille, refined tail, less chrome and recessed backlight.
1968
The Dodge Dancing Party - 1955 1968-02-24 was released on: USA: 24 February 1968
1968 - 1988.
If, by ECU you mean "Engine Control Unit", I don't believe a 1968 dodge pickup had one.
1960 through 1968.
JOSTEN'S