Yes it will, but.... I am not certain if the piston latch rod of the cadet is the same length as that of thecadet major, so it may not latch. I cannot remember if the pistons are the same length. They are the same diameter and logically they should be identical. The cylinder of the cadet major is longer of course, but that may be the only major difference. ( apart from the sights and trigger adjustment.)
Perhaps an owner of both has tried this swap of trigger blocks and can comment further...?
Pete.