Is 15 Degress aft too much mast rake for a h16?
This rake aft gives me about 1/8 of an inch of area meeting at the mast step and mast base, (at the stops), is this enough to safely keep from over rotating the mast?
All replies are appreciated!

Maximum mast rake with the sixteen is when you've gone block to block and still can maintain a little tension along the leech of the sail. It varies with the profile of the mainsheet block system you have. But in any case you should be able to use a low profile rig with max mast rake and still have enough rim left on the rotation stop to be sufficient. If not, you might have to replace the mast base. These sometimes get worn down, and are much easier to replace than the mast step.

Thanks for the info! I do not know if I have a low profile blocks or not. When they are off the boat the length, ( not including shackles), is about 14 inches, with three blocks on top and two on the bottom.
The mast base is only three years old and is in excellent shape.
Thanks again!