To couple the driveshaft to the motor (direct drive, no transmission) I needed an adapter to mate two pieces.
One is a PTO disc from a large tractor. It had a riveted hub with the right spline pattern for my motor, and it's slip fit like a driveshaft slip yoke would be:
And a Spicer 1350-series flange yoke.
Neither one of these parts is up to the task of handling the torque of the race motor, but they will get the truck moving for initial testing and a little fun. Another trick inside the motor, when the full race build happens will be a custom shaft with TH400 splines on the output side, so I can eliminate this adapter.
Finished adapter assembly:
Sorry for all the crappy pics. My camera was broken and I took a lot of these with my cell. Eventually, I bought a little Nikon, so the quality will get better.