That whale tale should help with getting on plane but the problem with that setup is the weight of the motor. My neighbor has an 1985 model 168 with a 150 ficht on it. The boat is rated at 150 hp. It will run in the upper 50's but could probably see more with setup and prop work but he is content with the way it runs now. He used to have a 85 Evinrude XP 150 on it that would push it to low 60's. He has to feather the throttle when coming off plane or the back end gets swamped. He runs a 25" 4 blade prop on his and with the weight of the motor you definately need a stern lifting prop.