I recommend that you go with the Rotary #15095 blades. These are notched high lift blades that are usually for Scag mowers. The will fit your Gravely. However, they are flat blades. That being said, I recommend that you get a set of blade spacers. The spacers need to be 1" OD x 5/8" ID x 1/4" thick. The spacers need to be placed between the blades and the spindles. Doing this will make up the difference of using the offset Gravely/Ariens blades. It will also keep your actual cutting height and deck volume the same.
Those Scag blades will really throw the grass and help keep the underside of your deck cleaner.
