[6] The Tempest's drivetrain features a rear-mounted transaxle connected to the engine via a torque tube,[2] giving the car a near-perfect 50-50 front-rear weight balance.

This allows it to be an unusually small 5⁄8 inch (16 mm) solid rotating shaft, inside the pressed steel square torque tube.

The Trophy 4 is cushioned by flexible rubber engine mounts designed to isolate the engine from the rest of the car, and its forces are further damped by the Tempest's unusual drivetrain that distributes these forces through the torque tube to the rear-mounted transaxle.

The timing chain in the Trophy 4 was originally the same as the 389, but was prone to stretch and break from engine vibration; a special high-strength version was developed as a replacement.

[citation needed] The Trophy 4 was dropped from the Tempest line when it upgraded from a compact to an intermediate for the 1964 model year.