Checking the driveshaft angle is not the best way. The center line of the pinion should be lower than the center line of the crankshaft by about 2 degrees for street use and up to 4 degrees for drag racing. An angle finder on the front balancer or even pulley, a machined spot on the bell housing, or even on the extension housing seal (if it's driven in flush and is smooth) in a pinch will give crank angle and the pinion yoke turned with the bearing cups vertical will give the pinion angle. Do not use the top of the differential housing or engine valve cover.
