If you are looking for a Ford part number then you may find the following website useful.
http://eucatparts.com/?action=cat_ford
It's not as good as the realoem.com website for BMW's but it is the best I've found so far.
Unfortunately, Ford had a bad habit of having multiple part types depending on the model so it can be difficult to decipher. (for example, Ford fitted eight different types of front ARB's to the Sierra).
I've already found it useful tracking down some rare parts.
31 Aug 2015, 8:09pm