I made a rack for my 1951 chevy 3100. Someone asked if i wanted to send him the measurements i used. So I tought: "why don't share it with the rest of the community?" So here they are. Note that i'm from the Netherlands so i use Centimeters. But I wrote the inches on it. I suggest to measure or convert it for yourself so they are correct. I also put the length between the poles in it. Check if they are the same as yours before you make the rack yourself!
If you measure from the pole on the side of the cab it is 26.6 inch (67.5 cm) till the first one and 51.8 inch (131.5 cm) till the second one. I also used 1.8 inch (4.5 cm) clearenance between the planks. I added another drawing to make it easier too see.
