The Jaguar 420 arrived in 1966 as a stop-gap between the Mk II / S-Type and the new XJ6 that would arrive in 1968. The 420 was a curious mix of S-Type rear and Mk X / 420G front styling which incorporated the Mk X squared-off front grille and twin headlamps.
Mechanically the 420 used a twin carb Mk X / E-Type 4.2 litre engine which blessed the new model with healthy performance figures. The 420 came with a limited slip differential and dual-circuit brakes. Options included power steering, auto and manual overdrive transmission.
A badge engineered version of the new 420 appeared alongside and was known as the Daimler Sovereign. This luxury version of the 420 was mechanically identical and shared the same body shell as the Jaguar. 420 and Sovereign production ended in 1968/69 with the arrival of the new XJ6 range.