The MGA Twin Cam steering rack is set a little farther forward to clear the crank pulley on the longer Twin Cam engine. This trait was also carried over to the "Deluxe" cars after end of Twin Cam production. The Twin Cam steering rack also has a longer input pinion shaft to locate the universal joint in same position as the standard cars (not to change the steering column length). The Twin Cam steering rack also has the Zerk fittings on the bottom side for easier access.

A picture showing the approimate 1-inch difference in length of the steering rack pininon shaft. Photo compliments of Ian Renshaw.

Notice the angled gear teeth on the pinion shaft. Gear teeth on the transverse moving steering rack are straight teeth cut perpendicular to the rack motion axis. The inout pinion shaft is positioned at an angle, not perpendicular to the rack. Therefore the gear teeth on the pinion shaft must be inverselt angled to cancel ouit the shaft angle so the gear teeth mate perpendicular to the rack axis. Difference between Right Hand Drive and Left Hand Drive steeriung rack will have the pinion gear teeth angled in opposite direction.

Pbotos and notes below from Christopher Cox via the MGA Twin Cam group on IO.
These show the Twin Cam steering rack (Right Hand Drive in this case) right side up and inverted. Aside from the longer pinion shaft, the grease fittings (Zerk fittings) are on the front or bottom pointing downward for access from below. For conversion, the oil nipples are relocated underneath by welding drilling and tapping.


Pinion shaft length outside the rack housing after conversion.


Non-adjustable steering column tube.



Non-adjustable steering column shaft.