I purchased a used motor from National Parts also known as Searchparts.com and had it shipped to a Ford Dealership. National parts requires you ship the part to a certified mechanic shop to verify warranty. Upon installation of the motor the mechanic was unable to get the motor to turn. Due to the extended lengh of the time the motor sat at a salvage yard the motor froze up. When I contacted national parts the suggested we disassemble the motor top determine why the the motor locked up. We refused to determine the problem because it would have caused more billable time from dealership to determine the problem. I suggested we return the motor for credit. National parts advertises a satisfaction gaurantee on their website. They agreed to take the motor back. When I finall got a credit back on my credit card they charged me freight and 20% restocking fee. National parts said that when the motor was returned to the salvage yard they had contracted with for the original purchase, They said the motor was not defective and turned OK. But I had 3 mechanics at a ford dealership who could not get it to turn with a 1\2 in breaker bar and the plugs removed. They took the word of a auto recycler who owned the motor to begin with. Then National parts told me that the dealership was Playing "games with me". I would almost beleive this if it weren't for the fact that the 17 year mechanic who installed the motor at the dealeship is engaged to my daughter and we have known him for over 3 years. The dealership had no financial gain in the return of the motor. I feel that the Auto recycler who originally sent out the motor did not check out the motor before it was shipped. The motor was out of a 2003 automobile that supposedly had 6900 miles on it. The motor locked up with age because it was not stored properly. I have filed a compalint with the BBB in Jacksonville but that was no help. national Parts just keeps saying the dealership misled me in shipping the motor back. But they did not even speak to anyone at the dealership. Which I had requested they do a number of times. This was never acheived.