Tony,
I know I've heard talk about this before but I didn't have any luck searching here for it either. There are guys using it on the 55-59 trucks with a kit from CPP. I went looking for that info and found this stuff.
CPP 55-59 Kit
A similar kit for 48-64 F*rd's

They also make a kit for a Saginaw box for the AD trucks and have a nice writeup for it here.
Another Good Pic Here

I know these aren't what you asked but I provide them to just give you an idea of the plan and a look at some pieces similar to what you'd need. On the pump I would think you'd be able to use a GM Pump, you'd just have to have lines made up with metric fittings on one end and GM style on the other.

I'd take a phone fishing expedition and call CPP and see what they have to say. Since they don't make anything for it I'm sure they'll be willing to talk to you about it. You might get the guy there that says "O' yeah, you need to use ...This.. this and this..

I'm trying to remember, on the 41-46 trucks the steering box sets down in the frame rail right and the shaft for the arm goes through the frame right? Not setting on top of the frame like on an AD truck.

Either way I'm sure more experienced bolters than me will chime in.

MONGO


Mongo's Garage
Vintage GM Truck's & Parts
https://mongosgarage.com