Triumph updated its Spitfire / GT6 range again in 1970 when it launched the Spitfire Mk IV / GT6 Mk III. The new cars received the new family tail treatment (like on the Stag / 2000 Mk II series), a new windscreen, and more modern wheels.
Other changes included a new optional overdrive arrangement and servo powered brakes. Rear suspension moved back to a simple swing-spring set-up which it shared with the new Spitfire model. Unfortunately the GT6 was dropped from the Triumph range in 1973 despite the Spitfires continued production.