NJAIRSTRIKE,

It depends on the plane you select. For a profile type plane for 3D choice is so it looks good on the plane. Most spinners in the 2-1/2" to 3" diameter range will work. Brands differ in the amount of offset needed. Du-Bro spinners have the backplate recessed and the Great Planes are flush. If your cowl is close to the prop then that may dictate the choice. For most sport planes these will work. Expect to do some filing on the nose cone to get a good fit especially with the APC props. I just installed an APC 12.25 x 3.75 in a Diablo 3D plane. The back plate also needed to be filed as the prop blade extednds behind the hub. If you want the best then Tru-Turn makes spinners already cut (or cut to order) for specific propellers and/or 3D. Really nice however cost can be in the $30+ range and require an adapter for an additional $8 in the smaller sizes. These are milled from solid aluminum bar stock.

Additional information Du-Bro vs. Great Planes spinners. The Great planes spinners use a phillips screw into the plastic backplate. Du-Bro uses hex bolts into aircraft bolts in the backplate.

EXCAP232