TALL deck is not going to be an eng swap---the rules TELL you what you have to have! Eng swap, quick change, or a non stock supercharger.
the Preveiouly unwritten "understanding is" it is NOT an eng swap if it used a head, manifold combination that was available on other production engs available in that body production series.( A BBC in a 55 Chev is an eng swap a tall deck BBC in a CAMARO ois NOT.
That has now been addressed a wee small bit in GT --with the new rules release.