[olddog]

You do not want 0 degree angle on the u-joints as the normal operating position. If there is 0 deg, the needles will not move, and they will wear flat spots and fail. Typically they recommend a minimum of 3 deg.

Some auto manufactures off set the engine and transmission to achieve the minimum angle. I think a few off set the differential. The pinion and the transmission have to be in the same plane length wise of the car. If they are not in the same plane or if the joints are not 90 degrees out of phase on the shaft, the sine wave oscillation of speed at the shaft is not canceled (adds to 0).

A Cobra has such a short drive shaft that minimal movement in the rear springs causes quite a bit of angle at the U-joints.