The 4.2 Mk X received the vastly improved, all synchromesh manual gearbox; it used a widened version of the new independent rear suspension as fitted to the E-Type and was fitted with the same engine. The 4.2 came with a substantial four-door saloon body that could easily seat 6 people. In spite of the car's bulk, it was not slow with a top speed of 120 mph. Standard mechanical items included power steering, independent rear suspension, a limited slip diff. The car was designed almost wholly with the US market in mind.