The Stovebolt Site Forums The Parking Lot Big Bolts Olds or Pontiac eng in GMC? know of such a thing

I think GMC used a Pontiac V8 back in those days, and Chevrolet used Buick engines. This was before they had V8's of their own. I have never heard of an Olds in any one of them from the factory. This might have been something that someone did themselves.
Jim