The Vitesse 1600, Mk1 2 Litre Vitesse and Mk1 GT6 inlet manifold has longer pipes, due to the shorter head on the earlier engine, than the Mk2 and Mk3 inlet manifolds. The Vitesse accelerator cable bracket tapped hole is not present on the GT6 inlet manifold. If you are after GT6 Mk3 inlet manifold ensure it has the central tapped holes to take the accelerator cable mechanism.
Dave