I build these chassis extensions so I could extend my chassis out by 140mm and add an extra axle. You need to print two of these. They are designed to fit into the existing (stock) axial chassis rails for an SCX10. I'm printing with PLA and am not sure how durable they will be. Time will tell! The design was going to include the holes for shock hoops, rear bumper, a cross brace, and the holes where they mount to existing chassis... but.. I think it'd be easy to drill these out.

I'll post pics of these on the truck when they are done printing and installed.