I've been real frustrated with customer service the last few years. I don't have any unpleasant experience with American Classic, but there is another often mentioned vender I've been vocal about several times.
They respond as if any difficulty is my fault or my misunderstanding. I finally decided they are right and that if I don't order from them we won't have any more problems. So far that approach is working for me and they don't seem to mind doing without my money.
Jeff I've been happy with parts the parts I've bought from LMC Truck for my '72. The are not the cheapest but I've never had a complaint about their service and I'm willing to pay a little more for that.
Open comment to any vendors reading this thread
There is a classic study that was published in Harvard Business Review about 1990 that shows that acquiring new customers is much more expensive than serving long-term customers and that retaining customers long-term results in much stronger profits.
These results can be measured and even forecast.
I'd encourage any vendor reading this to do some research on the subject and think about the future of their company. You may be focused on measuring near-term profits to the detriment of long-term customer value and the future health of your company.
If you don't know how to measure it get some help.