1992 Cadillac Deville Replacement

Where are you that they get that picky with inspections? I've never heard of a headlight catching fire.

Head light aimers are obsolete now due to all the different headlight designs. All service manuals list a procedure that involves placing targets, like a piece of tape, at a specified height, on the wall or garage door of the shop, then you back the car up a measured distance, commonly 20 feet, and aim the lights to hit those targets. In my opinion that is not real precise, and it is just a starting point. I prefer seeing where they're pointed while driving at night, then I make fine tuning adjustments. When you don't have a service manual to find the right height, measure from the ground to the middle of the headlight housing, subtract I believe it is two inches, (might be four inches), and that's the height to place the targets.

You may want to use the wall method with your old lights first to determine where to place the targets. That way, if the lights are okay now, you don't have to worry if the ground is level, and you'll get the left / right set the same as they are now.

A lot of headlight housings have bubble levels built in for the vertical adjustment. That accounts for sagging suspensions and varying weight in the car.