Yes, in the arrival photo.  Engine close up is of the companion car Rd Am, the next consecutive VIN.   Mine special order Charcoal Gray,  other Black.

Howdy Greg,  Yes, I recall our exchanges on this and many other topics those many years ago.  The only answer I had at that time was "estate" brakes.   It was within the last ten years, I think, that researcher Karl Pippart III came across the explanation of the "Strang Conversion" if I may label it with that moniker, to make this happen.  With that the light bulb came on brilliantly and the question was answered.  

John,  the exhaust manifold shown in the photo of the open front end are unique, and as far as has been determined, were one-off castings.  Meaning one pair and experimental at that point.   They are shown on the black, companion car to mine.  Obviously they required cutting up the inner wheel wells and rerouting everything on the left side well.   In later years Fred Kiekhaefer, ECK's son, stated he thought he had seen the pair stored in his personal Quonset hut at Mercury Performance division, however when the building was emptied, they were not discovered.

These are not the truck 4-bolt manifolds of '55 and '56 which were used on the race cars.  I presume that is what you have.  Neither are they the limited production high performance 4-bolts which were a new casting to clear the new torsion suspension of the '57 cars.   What they are, as stated, is one-offs and internally they have half inch larger passages!

Thanks! I will look in the morning for the number and alpha's  stamped on this Truck Block.

I wasn't "limiting" the truck 4-bolt exhausts to '55-56.   Just that Kiekhaefer dipped into the parts books those two years for "stock" parts for his race cars.   In '57 the truck manifs wouldn't fit with torsion suspension.   For '54 and earlier Carrera PanAmericana he had used totally production line parts.

I've never owned, nor been up close personal with a 501.  The difference in wheelbase could have allowed some room perhaps?   The tight points are the power steering box (if equipped) and the rear upper leg of the right front control arm.

David, Will do! I am learning a lot in this discussion..

John

3.73 would sound reasonable that this model/package of the Coronet would be delivered with that gear set with a Manual Transmission.