The best description of pinions is probably in the Jack French article around special building. It can be found in the Special Builders Guide and I think the Companion.
Essentially there are three design types for the post screw-in torque tube type axle. One with a RH retaining nut, one with a LH nut and the last type with a 1 1/8” step before the pinion which used a roller bearing to support the pinion. Ratios were 4.9, 5.25 and 5.125, although the ratios didn’t change precisely with the design features above. I suppose you could have a loose Nippy/van pinion of 5.625 but it’s unlikely since they break very easily.
The spring wrapping is called Denso tape but some love it and some believe that it’s the source of spring degradation and corrosion
Essentially there are three design types for the post screw-in torque tube type axle. One with a RH retaining nut, one with a LH nut and the last type with a 1 1/8” step before the pinion which used a roller bearing to support the pinion. Ratios were 4.9, 5.25 and 5.125, although the ratios didn’t change precisely with the design features above. I suppose you could have a loose Nippy/van pinion of 5.625 but it’s unlikely since they break very easily.
The spring wrapping is called Denso tape but some love it and some believe that it’s the source of spring degradation and corrosion