shorter diablo?

I`ve heard of people lengthening Diablos. Can the Diablo be made
shorter by simply moving the transom in towards the bow by say a foot
or foot and a half? Will this mean changes to the transom diamensions
or the side/bilge panels? It looks like it can be done fairly easy
due to the straight run in the aft section. Also, the angle to be cut
on the stem, is it constant or does it change degree`s over the
length of the stem?