Anyone know if they make an adapter to go from small shaft ssm3 to a large shaft ssm 3a

Yes they do, I bought mine from Rik at arneson industries.

Thanxs seems like all the used stuff is in a large shaft, and when you call a place like b-blades, the choice is much better for a big shaft
I'm guessing thats the surface drive company i saw a few scarabs and fountains with those drive not sure how long it takes to get on plane but im sure it flys when it gets there

I know this is an older thread but I had to custom make some for my arnesons to fit #6 props on my 19 spline only issue I have still is I have the short shaft asd6 and it's harder to have props made, I plan on eventually releasing them for sale but currently still testing