Measure the drivesahft angle and the pinion angle with your angle finder and then do the math to get the differences between the two, that is what is called the pinion angle in all of the old Mopar chassis manuals, believe it or not For instance, if the driveshaft measures 90 degrees on your angle finder and the pinon measures 87 with the pinion nose down instead of up you have 3 degrees differences in the correct way, if the pinion is pointed up then you need to rotate the rear end housing down 6 to 9 degrees to get 3 to 6 nose down in relation to the driveshaft. If the driveshaft measures two degrees left of the 90 degree mark looking at it from the drivers side and the pinion measures three degrees right of the 90 degree mark you add the two measurements up which comes to five degrees which will work fine on a Cal Track car, usually. Some Cal track cars need more and some need less. If the driveshaft reads two degrees left of the 90 degree mark and the pinion reads 3 or more degrees left of the 90 degree mark also then the rear end housing needs to be rotated down down to get the needed dergrees of difference. Nothing to it, huh Keep at it, get it done corerectly now and prevent damage later