Except for some of the engine brackets being different from the 302 to the 351, it will work.
The centerlink, where the idler arm connects, is straight on the 67/68 and dips a little bit on the 69. Other than that, they are the same and will interchange because the geometry only varies this small amount. All the mounting hole diameters, spacing and overall length is the same.
The power cylinder is the same 67 to 70.