advice on a 26' mono
 

hi guys I have a 28 (length on waterline prob about 26) offshore mono deep vee, no tabs. Just put 2x 250 pro xs mercs on her and really struggling to get it set up well. They obviously came with bravo 4 blade 24''s the holeshot is pretty good but it tops out at about 70 mph (when not trimmed and running right and light). I have had it going much faster and more stable with 28's but then the holeshot and powering out of turns etc is shiiiiiit. I dont really understand the hydrodynamics and side effects of the bigger blades more cup less blades etc. As sometimes with the same trim and conditions on a given day it will plane much faster and top out maybe 10-15mph faster... Any help would be greatly appreciated