This was a great upgrade for our Grizzly planer. Huge improvement in the smoothness of planned boards. But, beware, installation is not a trivial undertaking. Removing the old cutter head and installing the new one is not for the faint of heart nor mechanically challenged. Instructions provided are very minimal, dare I say inadequate. Grizzly does provide a YouTube video, but it too lacks many specifics. It took my wife and me the better part of two days to make the upgrade, not two hours! Last, I'm not sure why the spiral cutter head doesn't come as a kit with new bearings and oil seals - I had to order the latter items separately.