I am in the process of tracking down some parts I need for my 73 XLH. Several times I have come across a part that looks identical to the one I have but the part number is different than specified in my harley parts catalog. For example a part I am looking at may have the following part number 12345-70 (which the parts book may say is late 70 to early 72 - xlh,xlch). The next entry down for the same part may state the part I should be looking at is 12345-72 (late 72 to 75 - xlh, xlch). In this case can I use the -70 part or not?? Again the part looks identical pic wise but since I don't have it in my hands I can only go by what I see. Thanks and I await any responses..

 

You've got one of those early/late production problems. I ran into that for the first time with my bike on a stupid air cleaner element, of all things. This after owning it for over 25 years. I found out my bike was the "early" version.

Anyway, be careful of going by pictures. I usually go by the part number myself. The best thing to do is post up part numbers, pics, everything you have on the problem here and somebody will know what works or not.

 

In my view, you can most likely use the later part. You do have to look carefully though.
When Harley made a slight change in a part, the suffix was changed while the main part number stayed the same. I am uncertain what the criteria was to have a part change suffix, but it was not a major thing.

If it was a truly new part then it will have a different part number.
If you look closely on your machine you may find some parts stamped '-52 or -52A'. These are parts that have not changed since 1952 with the manufacture of the first K Model.
pg