-The first year of production for the Plymouth GTX was 1967. -The engine options were a 318 V8 or a 426 Hemi. -The other features available were a vinyl top, power brakes, power steering, and a Torque Flite automatic transmission. -The Plymouth GTX was not as popular as the Plymouth Road Runner. -The discontinued models that are similar to the Plymouth GTX are the Plymouth Satellite and the Dodge Charger.