I am running the same boat as yours with the 89 Evinrude and a 14.25 x 23 3 blade SS. The Boat really likes to have the motor tucked in the down position for starting out. Once out of the hole at 3/4 throttle tap up a few times (1/2 second each) on the trim control and you will see your speed increase slightly without a raise in rpm. Give it a few more taps till the RPM raise between 25-50 rpms and you have reached the maximum up trim you want to run. If you are in rough water keep it trimmed down and give it 1 second of up it will keep you on the running pad solidly. My boat will run 54 mph at 5500 rpms and 2 people. The Ranger will run very nicely at 38 mph with a dry ride and no kidney punching. If you have some flat water go ahead and trim it up at 1/2 throttle till the rpm raises 25 to 50 rpms then bump it down 1 tap and give it full throttle...Watch the rpms for the motors recomended rpms and then you can tell if you are over/under propped.
art