Re-packing the main electronics pod into a 3" housing

Has anyone tried cramming all the electronics from the 4" housing into a 3" housing? Currently doing this in autocad and it all seems to fit thus far and should be able to lop off another inch off the housing length at least, but has anyone done it before; were there any issues using the standard bluerov2 pan-tilt in conjunction with the 3" acrylic dome?