A couple of risers for longboard trucks. They're both 5 degree, you may need longer screws for the 9mm one. 

The 1mm riser is wedged with the higher side on the inside of the board, tilting the trucks outward. It's meant to increase turning capability (decreased turn radius, more sensitive/responsive turns). I made it for a stiff slalom longboard. 

The 9mm is meant for skateboard decks that have been converted to longboards (or any deck with wheel-bite and/or too much wobble). This one is wedged in the opposite direction to decrease turn sensitivity. The large spacing is meant to increase wheel clearance.

Print in TPU, ABS, or tough PLA(+). I suggest a minimum 25% infill with 4 or 5 perimeters. A wider nozzle and smaller layer heights will also improve strength. Honeycomb, adaptive cubic or gyroid for infill, anything that improves compressive strength. I wouldn't worry too much, there's no (or very little) shear forces acting on a riser.