PINION angle is the difference between the angle of the engine/trans centerline and the PINION, and NOTHING ELSE. U-JOINT angle is the difference between the driveshaft and the engine/trans in the front, and the driveshaft and pinion in the rear, and NOTHING ELSE. You want the centerline of trans and pinion to be parallel under power, with about 1-2* of u-joint angle to make the joints wear properly, and to cancel vibration. Measure with the weight on the rear axle. So, to make it easy, if the trans is level - 0*, you want about 2* down on the driveshaft, and the pinion level -0*- as a baseline. Add to the rear u-joint angle 0* for a 4 link, 1-2* for ladders, and 3-5* for leaf cars. So in this application, the trans would be 0* (level), you would have -2* front u-joint angle, the driveshaft would be angled down 2*, +6* rear u-joint angle, and +4* (FROM LEVEL) downward pinion angle for a leaf spring car. This gives the correct (-2* and +2*) U-JOINT ANGLES under power, after the springs wrap up 4*. My printer is down, so I can't draw it and scan it to post, but this is the correct way to measure U-JOINT and PINION ANGLES.