Robbie Patterson at Propeller Dynamics (same property where Lee Sanderson is located) He does excellent work and the mods improve handling and top end.
There's several guys that do it. Titus has 2 options I believe, one that chops off the nose and welds on a different cone (I wouldn't go that far), and then a milder 'mini-mod' if you don't want to go that far. http://www.low-h2o.com/
I'll be doing some sanding/grinding on mine after I get some good baseline numbers..........