So not much different to a standard, old and flogged out Range Rover? :p
I welcome the idea of a 454 RRC being created and it's not like it would be lacking room for a cooling system to cope with the powerplant.
Besides, next step when going from small block to big block, is a big blower. I would pay many monies to see a 8/71 sticking out of the bonnet of a RRC with a lumpy big block thumping underneath it.
Just sayin'...

