https://board.moparts.org/ubbthreads/ubbt...deck%20hemi.jpg
Back around 1974 I was at Barnett Race Cars in Atlanta with a buddy. One of the Barnett's (don't remember now which one) was welding chrome moly tubes into a 400 block and turning it into a Hemi block just like the picture above. the pistons were considerably shorter and he used a shorter stroke with the long rods to get a 396 cu inch Hemi for the lighter car and lighter rotating assembly.
Jerry