How similar is the '66 Valiant VC compared to my '66 US Dart?

There are similarities and differences. Engine and transmission parts are almost all the same, with the possible exception of some externals (starter motor comes to mind; the VC got an Australian-made Bosch direct-drive starter not interchangeable with the US-type Chrysler-built gear-reduction item). Other components are different but interchangeable (late VCs got an Australian-made alternator). Brake parts are largely similar. Ball joints, control arms, torsion bars, rear springs are all going to be the same. Windscreen and gasket are the same. Your car appears to have a VC dashboard in it. Rear axles are interchangeable as an assembly, but they are different so subcomponents won't swap. Body hardware (door latches, etc.) will swap, but the only 2-door VCs were the utes (pickup trucks). Other than that, there's no interchange between a VC and your car as regards trim, grille, hood, taillights, trunk/deck/boot lid, bumpers, etc.

Cheers Dan,

Thats what i need to hear :)

Im basically changing the bushings for the suspensions front and rear, and replacing the 9" drum brake shoes and master cyls. So I reckon they are the same i.e. early Valiant VCs suspension and brakes are the same as early US Darts?

Thanx again.

Syed