I realize that.. but the difference can be significant. You don't, definitely don't.. want to go up to a 14 inch prop. The 13-4 or 13-6 may work out, but it becomes a matter of experimentation. I don't recall what I was using on my OS 61 then my Super Tigre 75, but they were the same prop, as I recall. But, not the same as I was using on my OS 46 or 50.

I use an APC 15-10 on my OS 1.20 AX but this engine has much more power than even a 90. Much more.

I know this doesn't quite answer your question, but the answer is not specific to your engine/plane setup. Every one is different and will need a different prop.. and add to that, your altitude and weather conditions.. and all sorts of things begin to change.

CGr.