[Double Venom]

Terry,
That is a great drawing and explains all-but your dealing with a Cobra and the rear end is NOT going to be level or parallel with the tranny tail shaft to begin with. Your driveshaft is way to short to try and use the above. See how 'A3 and A4' are on the same plane? And the listed rear end is drawn under the assumption (4-wheel drive) it is NOT going to raise/twist under power like a coil/coil-over rear end.

Assuming your rear end is set at close to the above drawing, you STILL want the pinion 'pointing' down a couple of degrees so when the power is supplied it will come back to a maximum of A3 & A4.

There working angle of A5 & A6 is shown the way most cars are set up to be, but again the shortness of the Cobra drive shaft (18 +/- inches) normally doesn't allow this. This is where it is made up with using the control arms to twist the pinion in a negative fashion so when it does go under power and tilts back up, it doesn't go over -0- degrees (which could still give you driveline vibrations even at -0-).

Even IF you were able to duplicate the above drawing you would still want the pinion pointing slightly down to make up for any residual lifting/twisting up under load.

Does this help? Make sense?
DV