Here's a 289 with original magnesium spline drive Torque Thrusts. They are great for street or track.
Best seen by clicking "view full image" button to see the detail of the wheels.
I had to pursue this set for 6 years before I could get them away from the prior owner. I think they are 6 1/2" and 7 1/2".
I have put many track miles on these things. The only problem is the 2-earred knockoffs tend to tighten up alot and are tough to get off because they are so close to the spokes of the wheel, but a big lead hammer does the trick. Forget even the biggest rubber lead filled hammer-it won't work!