Need help picking a prop

[Fishhyren11]

I have an older aluminum prop on my 1984 115 Evinrude on my 1985 170.

Though I'm not certain, I have a feeling this engine has been rebuilt in the past...
My recifyier needs to be replaced, so I can't tell you what my RPMs are running right now.
I have a new rectifyier, but I need to find a shop manual that says how to replace it (looks like I just need a steering wheel puller to get the flywheel off to get to it).

Anyways, I'm wondering how do I figure out what is the best prop for this boat?
The previous owner gave me a SS prop, but it rubs, so it is either too big or needs a spacer?

I'm looking for a balance of speed and hull shot, right now my top end is ~ 36mph   If I'm the only one in the boat and we aren't loaded to the teeth I can get out very quickly, but if we add 3 more people I need them to stand to the front of the boat till I can get up.
Thanks!

[Capt. Bob]

Try this from our resident "prop scars".  
There's more out there (hell, I even posted on props once) and this is a good starting point. http://www.classicaquasport.com/phpbb3/viewtopic.php?f=5&t=2084&start=0&st=0&sk=t&sd=a&bookmark=1

[bdtsr]

Sounds like you have a 19 or 21" pitch prop. Prop for about 5500rpm LOADED. Make sure the motor is trimmed all the down and raise it as you come up on plane. A drop in pitch prop would give a better hole shot but less top speed. The stator is under the flywheel. The rectifier/regulator should be on the port side of the engine with 5 wires or on the top back between the "V" of the engine (if memory serves), 2 yellow, 1 red, 1 black, 1 gray. With the engine running you should have 20-24 volts AC present on the yellow wires, if not the stator is shot. The red and black wires should have about 14 volts DC if the rect/reg is working. Tach not working only points to the stator or rect/reg. The charging output is only 9 amps on these motors so be carefull not to load it too much. It is possible to kill the battery with engine running (killer stereo will do it).