My application is Arneson drives with 1.25" 19-spline shafts. After my repower I am thinking of changing props but they seem to be hard to find as I need the pitch to be in the 17-18 range. Anyone see any lying around?

You might be able to get a pair of spline adapters from Rik which would open up options for props.
There are a pair of what appear to be Michigan Ballistic 19 spine 14 3/8" NiBRAL x 21 on Kijiji up here.

17-18" pitch is pretty small. Are you turning them engine speed.

Are you running twins and need matched sets?
​Always harder to find.

I've been looking for sets of 19 spline props. Usually in higher pitch. I have 1.32 reduction with 25 pitch 5 blade Rollas, but need spares and maybe try something else.

+1 on the 25 or 26 spline adapter hub.

What's the boat and power, I'm trying to prop a boat right now this Asd 6s and actually had custom adapter's made to fit #6 props the problem im facing is too much stern lift.