Fig,
I make the kits for Jim Carter and The Filling Station. I might be able to help you sort out the mounting of your cab.
The wood blocks are added to the parts I supply so the PDF from Pat is good info. The only thing I see that I would change is that the bolts in all the trucks I have seen ('31/'38) are square head, not hex head.
The master cylinder reference only applies to larger trucks.
Feel free to call me at 573 864 6539 or direct email at the address below.

Mike