These cars usually have similar motor mounts...a 1" diameter tube with a nut welded inside one end. That's where the bolt goes from the engine mount.
Fab some smaller tubing to triangulate the mount. I like to use 32-48 Ford donut mounts. They go between the engine mount and the frame mount. Just take a good look at the mount on this dirt car chassis and you may be able to figure it out.
Just like anything else if you stare at it long enough you can figure out how to make it work!