Thats a funny story...

The standard engine for a 1966 Caprice was a 283 with a 2 Bbl.
The 327 had a 4 barrel and could have a Rochester, Carter, or Holley carburetor.
If the car is all original and came with a 327 there willl be a 327 "numbers" above the crossed flags on the side of the front fenders front area - front of wheel opening.
Its possible that the 4 barrel carb. and intake manifold has been replaced with a 2 Bbl and intake and air cleaner from a 283.....or..?