1973 Dart headlight aiming diagram
Glad you found it. It's 25' headlight to wall.
Its probably similar or same as earlier years. I think this is from my '68 Plymouth FSM. High beam adjustment is only for 4 lamp systems.
If you've switched headlamps to a different pattern, such as ECU, then its a little different.
Dan Stern has that info on his website, ieven if its a bit wordy you can skim through to get what you need.