500 series steering box in 69 c20

[Aus69c20]

Hi everyone. I'm new to the forum, from Melbourne Australia and recently purchased a 69 custom c20 with 396, a/c and pwr steer. Great truck and just trying to learn as much about it through the forum as I can.
I want to quicken up the steering ratio and thought a cpp 500 series steering box would do the job. they tell me they can't guarantee it will fit on a 3/4 ton truck.
My questions are has anyone gone down this road with a c20?
Did it fit?
Is the c20 pwr steer the same as in the c10?


Thanks in advance and I'll try post some photo's of the truck.