My '37 has the shocks at 19 degrees forward from vertical. It had some 3/8" flat bar welded to the frame when I got the truck, the top has a 90* bend for the top shock mount, they are pretty close to straight up and down. I have to use a Pinto rear shock due to the length restriction so I have very few choices when looking for shocks. I added a piece to the top mount to let the shock lean forward to take some of the efficiency away.
I have leaf springs from Detroit Spring, they custom made them for the weight of the truck, I wanted a softer ride and wasn't worried about the load capacity. They work good and ride nice, but the truck still has that four leaf spring ride. The front still is a little stiff but much better then the solid ride it had with stock '37 springs. Leaning the shocks made a difference, and one of these days I am going to lean them some more.
I attached the shock efficiency chart so you can see what the angle does to shock performance. It's a little misunderstood, the shock it self doesn't change, what does change is how much it compresses and extends while driving. The more it lays over, the less it moves in and out, thus reducing it capacity to control bounce. It's a good way to fine tune ride quality.
