I think the problem is when when people don't understand the difference between 5 degrees relative to the ground and 5 degrees relative to the centerline of the crankshaft. The numbers we read on the protractor or angle finder are relative to the ground. You can say it doesn't matter and be right, but it's still the numbers that we read on the gauges. To somebody who has never done this before that can be confusing.
If somebody ask " What angle should I run my pinion at?" and the reply is "5 degrees down" then the person who is asking is likely to put a angle finder on the rear end, pull the pinion down until it reads 5 degrees and weld it.
The people on this forum are pretty smart. It's not that it is too hard but " 5 degrees down" is not enough information for someone who doesn't know how to do it or doesn't know that 5 degrees down relative to the ground and 5 degrees relative to the crankshaft centerline can be the same or it can be a long way off.
