nebs... Rig it on the potential masts and see... Generally, the smaller mast will most probably lead to a softer leech (a little less power and a little more performance off the wind). The longer mast (stiffer) will probably make for a stiffer rig, encourage early planing and better upwind performance... Has it got an adjustable head

at 486, sounds as though it should rig on a 460.
Good luck...