I'm hoping to get some people to share there Arneson setups so I can start to get an idea what size props to be shopping.
Twin engine
V-bottom 31'
Current ratio 1.32
Torq expected 900
Speed predicted 100-105
Prop diameter 17-18"
Rake 18 deg

So using this information I show a 28 pitch prop with 14% slip gets in the low 100s... Based on this I think the 1.32 ratio should be doable and no need to spend 5k having them converted to 1.56. I would greatly appreciate any help from those willing to share their existing set ups. I've found plenty of posts with what props, but without knowing the ratio it doesn't help.

I have a 35 non-step Fountain, my engines put out around 800hp , I run a set of asd7's with a 1.32 gear ratio and in good conditions I can go 105mph . My best overall set of props are 18dia 20*rake 31pitch.

Thank you! That helps a lot. What rpms do you reach at the 105? Would you by chance know your cruise rpm and speed?

When the boat reaches 105 I am turning about 5500 rpm . I don't pay much attention to my cruse speed and rpm but the info is in my prop testing log book and i can take a look , what do you consider your cruse speed to be ?

Usually cruise about 3500 rpm.

Depending on how the trim is set but usually at 3500rpm i am traveling about 68 to 70 mph

rake is everything with Arnesons, eighteen degrees minimum. Big diameter and more blades after that.