I have started to put back together a 66 Dart that I tore down about 20 years ago. I started to install the torsion bars, and went online to see how they need to be clocked. Now it sounds like there is a left and a right, and also a front and rear to each bar. Any way to tell which is which? Markings on the ends are hardly legible, but one appears to have the number 625, the other may have 445 on it with a circle around the center 4. Any help is appreciated--thanks!

Sounds like you need access to a 1966 Dodge factory service manual, I usually buy one for each car I buy and work on. I can't remember all the details on what end should be forward and which end installs into the tranny crossmember and how to properly clock them :whiney
good luck on yours

Doesn't the "White Book" list the numbers for left and right torsion bar fitment for model and year? And if you can read one torsion bar number it should be simple from there. Also the diameter of the torsion bar will help to ID them too. Obvious the larger diameter (thickness) is the heavier (more spring tension) torsion bar. When I say heavier/spring tension it will also weigh slightly more too. Not sure but I thought or think the more tension torsion bar(s) were on the right passenger's side due to the engine offset to that side??

End to end doesn't matter but left and right do. The hex ends are clocked for each side. The numbers stamped should help determine which side is which.

The numbers are mostly not legible, but one definitely has the number 625 on it, and one may have an "L" . From reading different websites, it sounds like the hex ends are clocked 30 degrees from front to rear.

After getting more of the paint (olive green) off the ends, one bar is L and one is R. All is good now.

The 3 digit number will be stamped on the side that goes in the crossmember. Even last digit is right side, odd is left side. 624/625 is 1964 A body w/ 273 engine.
Side and front to back do matter if installing used bars as they have a memory.
If they are marked L & R then someone marked them. I have never seen them marked from the factory except for the last 3 digits of the part number.

Many have the L and R on them. Here is some info. http://www.moparts.org/Tech/Archive/susp/7.html

Yes numbered and have L and R on them. Put a little grease and it slides right in. Put the clips and dust covers
Only problem one would have is rusted or scratched bars.
If not no problems with used bars