OK ,Question,I've got 468 fresh,turning 4600-4700,60mph,sometimes if im lucky 61.7,best run yet,all GPS verified ,berkley 12JB,with good condition berkley A impeller,both impeller and wear ring changed sametime,got a hyd place diverter as well and loader grate.anyway I need more speed, I dont want to mess with my engine as I just did it last year and I'd like to get some running out of it before I spend anymore so I'm thinking impeller I was hoping to get some opinions on what type and size, I was thinking about a B to try and bring my rpm up to 5000 or maybe a little more,my motor should be able to withstand that no problem .I sure would like to see 65mph,got a couple expensive prop boats on the lakes I would like to pass by,65 would do just fine.