Before Posting, Please Read Our Posting Guidelines Below.
1. Use the full 4 digit year for everything you are asking your question about. Example: 1962, 1988, 2000, 2011 2. Include the correct name of your Whaler model. Example: Montauk 17, Montauk 170, Outrage 26, Outrage 260 3. Include the length when necessary. Example: 16, 17, 18, 20, 22 4. Do not post your email address anywhere on this site as it is already in your user profile.
Both the OMC/BRP SST/Viper propellers and the Stiletto Advantage are great props for that boat/motor combination.
The precise pitch will depend on the gear ratio and redline of your 1988 Johnson 70, which I do not recall off the top of my head. It changed in the late 1980s or early 1990s.
Your motor's owner's manual will contain the gear ratio/RPM information.