One solution could be to 3D print the parts and then make silicon molds and cast the parts in high strength mineral filled resin. Its a relatively inexpensive process you can do yourself (with a little practice). Mineral filled resins are very strong and are routinely used to prototype parts that will be exposed to high stresses. The downside is that the resin is heavier than ABS but depending on the size of the part, the increase in weight could be negligible.
I read recently of the availability of new filament materials that have chopped carbon fiber entrained in the spooled material for FFD printers. It will be interesting to see the strength characteristics of those. Thanks...TP