Dave,
Rocking horse droppings, lmao
I guess that's like saying they're as common as a chicken with lips?
Re: size, an E40D is
longer than a C6 moreso than it is
bigger:
You can clearly see the extra length added just aft of the bellhousing, for the overdrive planetary.
I would bet no-one is running an E40D in a Cobra yet, but maybe you will get a response in this thread from someone with one in a truck or passenger car.
Some places to consider are
Baumann Engineering and
Lentech.
Chris