For 1970, Plymouth updated the grill and the rear. Of all the front end treatments of this body style, the 1970 grill looks the best. Other changes included an updated hood with a much cleaner looking hood scoop. On the rear quarter panel a simulated scoop was added that detracted somewhat from the clean lines of the previous year.

After four years, Plymouth finally added a third engine option to the GTX. Now buyers had a choice between a 426 Hemi, a 440 Super Commando with a four barrel carburetor or the new 440 Six Barrel. The 440 Six Barrel has a trio of two barrel carburetors mounted on an Edelbrock aluminum manifold. This set up was good for about 35 hours power over the standard Super Commando 440.

In keeping with the performance theme, Plymouth equipped all the GTX models with their most durable suspension. It was the same suspension that came standard with the Hemi equipped models. The Hemi suspension included 11 inch drum brakes with the option of disk breaks up front. Heavy duty shocks, torsion bars, front stabilizer bars and additional rear leaf springs were all included.