The car was on e-bay and has recently ended/sold. I wasn't able to see the car so I guess we'll never know. All I had to go by were photos of the car. I can't understand why the car would have had a big block heater core unless someone changed it from small block to big block during its life, or changed the vin and trim tag? Here's a link to the ended auction.
X11 Big Block
Here is another X11 big block that I haven't been able to get any information on. Anybody in Virginia that can take a look?
X11 Big Block #2
Mike