I know someone that worked as a Ford salesman, When the SOHC 4.0L motor came out. He was also working for Ford when the Trac came out. That is what started the conversation. He told me That the SOHC 4.0L motor was a joint design, between Ford and Toyota. I told him I had a hard time beleiving that. Reason I told him was the cam chain design, didnt' seem to be up to Toyota' qaulity, IMO. I have never heard this before. I can see engineering differences, I would have done. I do know that various manufactors have helped each other in some engineering issues. Do any of the members know the truth. I knew nonthing of this motor until I purchased my '04. This guy worked for Ford about 5 yrs. Made it hard to argue With him. Him being in sales he might have been hearing rumors.