That makes sense, a NASCAR research type engine. The fact that Shelby got one does say a lot about his "pull" within Ford management at the time.
With talk of removing support for him at some point it must have a been a "love/hate" relationship.
I'm guessing Ford was not "that happy" about having to go to Shelby to "fix" their GT-40. I would think that was really a burr under the saddle for Ford management.
Ernie