Ken ,I found his on the DN articles page. Its similar advice to yours.
I wish it gave an over all length and a pivot hole location.

If you could guess is this a 30'' or a 36'' long runner?


http://www.idniyra.org/articles/runner_terms.htm



If it is a 36'' long should I use these dimensions on the next link
for pivot hole location and work the rest of the numbers from there?

http://www.idniyra.org/articles/inserts.htm

I am thinking of 36'' for the rear and 26'' or 30'' for the front.
I'm not crazy about the bullnose profile . I will put more entry curve
so the runners can have more of a chance of riding up an obstruction.
I'm thinking 4'' high overall with no down word turn on the top
surface like the bullnose link drawing.
We are thinking of trying D2 tool steel.The stiffeners will be 2 .5''
x 2'' flat bar drilled an tapped mounted on edge to form a tee shape
when mounted.

Where do you have your runners hardened?

The second option is to go for 30'' rear with less .008 for stickier
conditions.

Which pair would you build first?

Thanks
John