The first generation of Plymouth GTX was introduced for the 1967 model year. The GTX was a high performance two door car based on the Plymouth Belvedere. The GTX was available as a hardtop or convertible, and was fitted with a 440ci (7.2L) V8, or a 426ci (7.0L) Hemi V8. The first generation GTX was only available for the 1967 model year, and was replaced by the Second Generation Plymouth GTX.