All of the AT1, CT1, DT1, RT1 type bikes have the right spline.
All of the MX and DT250/360/400s have the right spline.
All of the early YZ250/360/400s with the pinch-bolt in the lever have the right spline.
All of the early IT250/400s with the pinch-bolt in the lever have the right spline.
The early type (single cam) XT250s have the right spline.
I'm sure that there are others, but those ones I know.
I can't talk sensibly about whether they'll clear the frame, except to say that I'm pretty sure an AT1 or CT1 lever will NOT clear.