I am not going to tell you what prop to get as I am having issues with hitting the correct rpm range myself. But I do have a Targa with a 115 Optimax and I went with the Vengence from Merc and love the prop, but have recently figured out my rpms are to high full throttle. So look up or ask a pro what your rpm range should be, turns out mine should be 5500-5700 and I am over that. Even though he got mine wrong I would still if your in the north metro talk to Rapid Marine. If you try it and its not what you wanted or should be and take if back right away they will exchange it no problem. Hope this helps.