Replacing steering column on 66 Dart - questions

Yeah, if the coupler is tight and has a good rubber boot, leave it alone. As for centering the wheel, don't file or alter the master spline. All you have to do is turn one tie rod one way, and the other tie rod the same amount, the other way. Be very precise on turning the tie rods so you don't change your toe-in setting or you'll have to get the front end aligned. What are you replacing your column with? A different column? The automatic columns are '66 only you know.... If you are going to disassemble the column, do yourself a favor and get a new seal for the bottom of the tube. That's pretty much the first thing that needs to be installed when you reassemble.