Re: What size stainless??
I suggest you read the sticky at the very top of this forum titled READ THIS FIRST. You do not change pitch on a whim. Adding pitch can only work to your advantage if the engine is under propped (too little pitch). Decreasing pitch can only work if the engine is overpropped (too much pitch). At this stage we have no idea whether you should increase, decrease or keep pitch the same due to lack of meaningful data. I would also suspect the prop you have is incorrect since that motor, if it is a relatively late model, typically runs a 12-1/4 x 15 on a 15 - 17 foot boat. 13-1/4 says its from a larger motor. Generally, but not always, one inch drop in pitch is called for when going from aluminum to SS. SS is generally, but not always, more efficient that aluminum so if the prop is wrong now (over propped) it will be even more overpropped with the SS of the same diameter and pitch.
