Call ford? I'm thinking they might have more than one phone number.
What if a roller set could be had for not much more than what you are planning to pay now? I no longer build a strong motor without a Roller Valve Train. The difference is incredible, A Friction Valve Train can rob up to 20% or more of your potential output from an Engine.
If you are willing to check it out I will try to find you the connection to these parts as a fellow Ford Fan.
I was weaned on building swap out Exchange Motors for "Weekend Bracket Racers" and currently do personal custom dynamics work for the same as my principle occupation.
When I no longer have the right to protect my own person or property...my person and property have become public property in common.
