I have never heard of this, but I guess anything is possible when you ordered these cars back in the day.. Maybe somebody wanted the ultimate sleeper look with the L78 engine option and ordered it that way?? Unless specially ordered this way, I don't think Chevy ever made an L78 nova that did not have the SS option or goodies..
I do know of a local car (69 Nova) running around that the original owner's son now owns. He stated that his father special ordered the car with all of the SS options minus the hood louvers and badging. The car has the original hi-po 350 in it that would have came in the SS models. This car was special ordered this way from a local dealership here in Ohio and is the "real deal".
Rich