My lower is 1.81 not 1.75..HPDI. difference?

[87gtNOS]

Well without knowing, my 250 HPDI has an OX66 lower on it. No biggy, not gonna notice as I won't be going 85 mph!

However, been working on getting past chine walk at 66mph and feel 70 might be peak.
Have a Croxton Razor4 25p that I had sent back to Mark to add some cupping.
So with that said, spec'ing out my prop I can assume was based on HPDI 1.75 gears. I pulled my plugs yesterday and spun motor by hand...I have a 1.81 lower.

My question is...do I send Mark my prop to be pitched to a 26 or look for a HPDI lower?
Will I notice much difference? I could use some midrange cruise mph...
Thoughts?

[21XDC]

The ox66 LU is only good for 82-83 mph... The gear ratio will only effect your prop pitch selection by 1-2. The OX66 LU has more bow lift.

[87gtNOS]

Understandable about the bow lift, but I did have Mark add cup, as I was not satisfied with the lift I was getting!

So it looks like I need to have this prop repitched some....

[21XDC]

You might want a large diameter three blade for more bow lIft.

[Bubba201proxl]

As 21XDC said I would try like a 25T-1 or a 27T-1 depending on load. If your turning that 25P Razor 4 which is pretty stiff I would go with the 27T-1.